Further clean up all code, use the exception mechanism across the board, and make error codes only used internally, when asserting a problem, and not externally represented.

Calling the operating system's API makes a lot more sense.
Exceptions are definitely thrown for non-existent files.
Formatting the source code makes it more readable.
Remove the direct use of the c++ 2011 type trait, All switched to c++2020 concepts and type constraints.
Update README.md

CMakeLists.txt

@@ -1,197 +1,53 @@
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.26)
+project(mio LANGUAGES CXX)
 
-#
-# Here we check whether mio is being configured in isolation or as a component
-# of a larger project. To do so, we query whether the `PROJECT_NAME` CMake
-# variable has been defined. In the case it has, we can conclude mio is a
-# subproject.
-#
-# This convention has been borrowed from the Catch C++ unit testing library.
-#
-if(DEFINED PROJECT_NAME)
-  set(subproject ON)
-  if(NOT DEFINED INSTALL_SUBPROJECTS)
-    set(INSTALL_SUBPROJECTS ON CACHE BOOL "Install subproject dependencies")
-  endif()
-else()
-  set(subproject OFF)
-  set_property(GLOBAL PROPERTY USE_FOLDERS ON)
-endif()
-
-project(mio VERSION 1.1.0 LANGUAGES C CXX)
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
-include(CMakeDependentOption)
-include(CMakePackageConfigHelpers)
-include(CTest)
-include(GNUInstallDirs)
-
-# Generate 'compile_commands.json' for clang_complete
-set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
-
-#
-# mio requires C++ 11 support, at a minimum. The `CMAKE_CXX_STANDARD` variable
-# is referenced when a target is created to initialize the CXX_STANDARD target
-# property.
-#
-# ** NOTE **
-# This is a directory scope variable. This has several implicitations.
-#
-# 1. It DOES NOT propegate to parent scopes (such as parent projects)
-# 2. It hides cache variables of the same name for this directory and below
-#
-set(CMAKE_CXX_STANDARD 11)
+# Set C++20 as the minimum required standard
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-#
-# The `mio.testing` options only appear as cmake-gui and ccmake options iff
-# mio is the highest level project. In the case that mio is a subproject, these
-# options are hidden from the user interface and set to `OFF`
-#
-# Iff mio is the highest level project, this option is defaulted to the value
-# of the traditional course grain testing option `BUILD_TESTING` established by
-# the CTest module
-#
-CMAKE_DEPENDENT_OPTION(mio.tests
-  "Build the mio tests and integrate with ctest"
-   ON "BUILD_TESTING; NOT subproject" OFF)
+# Enable CTest support if BUILD_TESTING is enabled
+include(CTest)
+if(BUILD_TESTING)
+  enable_testing()
+endif()
 
-#
-# On Windows, so as to be a "good citizen", mio offers two mechanisms to control
-# the imported surface area of the Windows API. The default `mio` target sets
-# the necessary flags for a minimal Win API (`WIN32_LEAN_AND_MEAN`, etc.) on
-# linking targets. This is, in our view, the conservative behavior.
-#
-# However, an option is published in the cache allowing client to opt out of
-# these compiler definintions. This preference will persist in the installed
-# cmake configuration file, but can be modified by downstream users by way of
-# the same cmake cache variable. This allows intermediate consumers (e.g. other
-# libraries) to defer this decision making to downstream clients.
-#
-# Beyond the option-based mechanism, two additional targets,
-# mio::mio_min_winapi and mio::mio_full_winapi, are specified below for those
-# that expressly requiring either the minimal or full windows API, respectively.
-#
-CMAKE_DEPENDENT_OPTION(mio.windows.full_api
-  "Configure mio without WIN32_LEAN_AND_MEAN and NOMINMAX definitions"
-  OFF "WIN32" ON)
-
-#
-# When the end user is consuming mio as a nested subproject, an option
-# is provided such that the user may exlude mio from the set of installed
-# cmake projects. This accomodates end users building executables or
-# compiled libraries which privately link to mio, but wish to only ship their
-# artifacts in an installation
-#
-CMAKE_DEPENDENT_OPTION(mio.installation
-  "Include mio in the install set"
-  "${INSTALL_SUBPROJECTS}" "subproject" ON)
-mark_as_advanced(mio.installation)
-
-#
-# mio has no compiled components. As such, we declare it as an `INTERFACE`
-# library, which denotes a collection of target properties to be applied
-# transitively to linking targets. In our case, this amounts to an include
-# directory and (potentially) some preprocessor definitions.
-#
+# Create an interface library "mio" to provide the include directory.
+# It is assumed that the headers are located in "single_include/mio".
 add_library(mio INTERFACE)
-add_library(mio::mio ALIAS mio)
+target_include_directories(mio INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/single_include)
 
-#
-# The include directory for mio can be expected to vary between build
-# and installaion. Here we use a CMake generator expression to dispatch
-# on how the configuration under which this library is being consumed.
-#
-# We define the generator expression as a variable, such that the logic
-# need not be repeated when populating source file paths.
-#
-string(CONCAT prefix
-  "$<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include>"
-  "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>")
-
-target_include_directories(mio INTERFACE ${prefix})
-
-if(NOT mio.windows.full_api)
-  target_compile_definitions(mio INTERFACE
-    $<BUILD_INTERFACE:WIN32_LEAN_AND_MEAN>
-    $<BUILD_INTERFACE:NOMINMAX>)
+# Add a basic test executable that is built on all platforms.
+# Note that the test source file is assumed to be located at "test/test.cpp".
+add_executable(mio.test ${CMAKE_CURRENT_SOURCE_DIR}/test/test.cpp)
+target_link_libraries(mio.test PRIVATE mio)
+if(BUILD_TESTING)
+  add_test(NAME mio.test COMMAND mio.test)
 endif()
 
+# Windows-specific targets (only built on Windows)
 if(WIN32)
-  add_library(mio_full_winapi INTERFACE)
-  add_library(mio::mio_full_winapi ALIAS mio_full_winapi)
-  target_include_directories(mio_full_winapi INTERFACE ${prefix})
-
-  add_library(mio_min_winapi INTERFACE)
-  add_library(mio::mio_min_winapi ALIAS mio_full_winapi)
-  target_compile_definitions(mio INTERFACE WIN32_LEAN_AND_MEAN NOMINMAX)
-  target_include_directories(mio_min_winapi INTERFACE ${prefix})
-endif()
-
-#
-# In order to collect mio's header files in IDE tools such as XCode or Visual
-# Studio, there must exist a target adding any such header files as source files.
-#
-# Given mio is an interface target, source files may only be added with the
-# INTERFACE keyword, which consequently propegate to linking targets. This
-# behavior isn't desirable to all clients.
-#
-# To accomodate, a second target is declared which collects the header files,
-# which links to the primary mio target. As such, the header files are available
-# in IDE tools.
-#
-add_library(mio-headers INTERFACE)
-add_library(mio::mio-headers ALIAS mio-headers)
-target_link_libraries(mio-headers INTERFACE mio)
-
-add_subdirectory(include/mio)
-
-if(mio.tests)
-  add_subdirectory(test)
-endif()
-
-if(mio.installation)
-  #
-  # Non-testing header files (preserving relative paths) are installed to the
-  # `include` subdirectory of the `$INSTALL_DIR/${CMAKE_INSTALL_PREFIX}`
-  # directory. Source file permissions preserved.
-  #
-  install(DIRECTORY include/
-    DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}"
-    FILES_MATCHING PATTERN "*.*pp")
-
-  #
-  # As a header-only library, there are no target components to be installed
-  # directly (the PUBLIC_HEADER property is not white listed for INTERFACE
-  # targets for some reason).
-  #
-  # However, it is worthwhile export our target description in order to later
-  # generate a CMake configuration file for consumption by CMake's `find_package`
-  # intrinsic
-  #
-  install(TARGETS mio mio-headers EXPORT mioTargets)
-
-  if(WIN32)
-    install(TARGETS mio_full_winapi mio_min_winapi EXPORT mioTargets)
+  # Unicode version: add the UNICODE compile definition.
+  add_executable(mio.unicode.test ${CMAKE_CURRENT_SOURCE_DIR}/test/test.cpp)
+  target_link_libraries(mio.unicode.test PRIVATE mio)
+  target_compile_definitions(mio.unicode.test PRIVATE UNICODE)
+  if(BUILD_TESTING)
+    add_test(NAME mio.unicode.test COMMAND mio.unicode.test)
   endif()
 
-  install(EXPORT mioTargets
-    FILE mio-targets.cmake
-    NAMESPACE mio::
-    DESTINATION share/cmake/mio)
+  # Full WinAPI version (adjust additional settings as needed).
+  add_executable(mio.fullwinapi.test ${CMAKE_CURRENT_SOURCE_DIR}/test/test.cpp)
+  target_link_libraries(mio.fullwinapi.test PRIVATE mio)
+  if(BUILD_TESTING)
+    add_test(NAME mio.fullwinapi.test COMMAND mio.fullwinapi.test)
+  endif()
 
-  write_basic_package_version_file("mio-config-version.cmake"
-    VERSION ${PROJECT_VERSION}
-    COMPATIBILITY SameMajorVersion)
-
-  configure_file(
-    "${PROJECT_SOURCE_DIR}/cmake/mio-config.cmake.in"
-    "${PROJECT_BINARY_DIR}/mio-config.cmake"
-    @ONLY)
-
-  install(FILES
-    "${PROJECT_BINARY_DIR}/mio-config-version.cmake"
-    "${PROJECT_BINARY_DIR}/mio-config.cmake"
-    DESTINATION share/cmake/mio)
+  # Minimal WinAPI version: minimal Windows API configuration.
+  add_executable(mio.minwinapi.test ${CMAKE_CURRENT_SOURCE_DIR}/test/test.cpp)
+  target_link_libraries(mio.minwinapi.test PRIVATE mio)
+  if(BUILD_TESTING)
+    add_test(NAME mio.minwinapi.test COMMAND mio.minwinapi.test)
+  endif()
+endif()
 
   #
   # Rudimentary CPack support.
@@ -209,15 +65,14 @@ if(mio.installation)
   #
   # See `cpack --help` or the CPack documentation for more information.
   #
-  if(NOT subproject)
-    set(CPACK_PACKAGE_VENDOR "mandreyel")
-    set(CPACK_PACKAGE_DESCRIPTION_SUMMARY
-      "Cross-platform C++11 header-only library for memory mapped file IO")
-    set(CMAKE_PROJECT_HOMEPAGE_URL "https://github.com/mandreyel/mio")
-    set(CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE")
-    set(CPACK_PACKAGE_VERSION_MAJOR "${PROJECT_VERSION_MAJOR}")
-    set(CPACK_PACKAGE_VERSION_MINOR "${PROJECT_VERSION_MINOR}")
-    set(CPACK_PACKAGE_VERSION_PATCH "${PROJECT_VERSION_PATCH}")
-    include(CPack)
-  endif()
+if(NOT subproject)
+ set(CPACK_PACKAGE_VENDOR "mandreyel")
+ set(CPACK_PACKAGE_DESCRIPTION_SUMMARY
+    "Cross-platform C++20 header-only library for memory mapped file IO")
+ set(CMAKE_PROJECT_HOMEPAGE_URL "https://github.com/Twilight-Dream-Of-Magic/mio")
+ set(CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE")
+ set(CPACK_PACKAGE_VERSION_MAJOR "${PROJECT_VERSION_MAJOR}")
+ set(CPACK_PACKAGE_VERSION_MINOR "${PROJECT_VERSION_MINOR}")
+ set(CPACK_PACKAGE_VERSION_PATCH "${PROJECT_VERSION_PATCH}")
+ include(CPack)
 endif()

README.md

@@ -1,5 +1,5 @@
 # mio
-An easy to use header-only cross-platform C++11 memory mapping library with an MIT license.
+An easy to use header-only cross-platform C++20 memory mapping library with an MIT license.
 
 mio has been created with the goal to be easily includable (i.e. no dependencies) in any C++ project that needs memory mapped file IO without the need to pull in Boost.
 
@@ -15,178 +15,516 @@ Furthermore, Boost.Iostreams' solution requires that the user pick offsets exact
 Albeit a minor nitpick, Boost.Iostreams implements memory mapped file IO with a `std::shared_ptr` to provide shared semantics, even if not needed, and the overhead of the heap allocation may be unnecessary and/or unwanted.
 In mio, there are two classes to cover the two use-cases: one that is move-only (basically a zero-cost abstraction over the system specific mmapping functions), and the other that acts just like its Boost.Iostreams counterpart, with shared semantics.
 
-### How to create a mapping
-NOTE: the file must exist before creating a mapping.
+### How to Create a Memory Mapping
 
-There are three ways to map a file into memory:
+> **Note:** The file must exist and be non-empty before mapping.
+
+There are two primary ways to create a memory mapping:
+
+#### 1. Using the Constructor
+
+Directly construct a memory mapping. On failure, a `std::system_error` is thrown.
 
-- Using the constructor, which throws a `std::system_error` on failure:
 ```c++
 mio::mmap_source mmap(path, offset, size_to_map);
 ```
-or you can omit the `offset` and `size_to_map` arguments, in which case the
-entire file is mapped:
+
+You can also omit the `offset` and `size_to_map` parameters to map the entire file:
+
 ```c++
 mio::mmap_source mmap(path);
 ```
 
-- Using the factory function:
-```c++
-std::error_code error;
-mio::mmap_source mmap = mio::make_mmap_source(path, offset, size_to_map, error);
-```
-or:
-```c++
-mio::mmap_source mmap = mio::make_mmap_source(path, error);
-```
+#### 2. Using the Member Function
+
+Alternatively, create an uninitialized mapping and then invoke the `map` member function. Like the constructor, this API throws an exception on error.
 
-- Using the `map` member function:
 ```c++
-std::error_code error;
 mio::mmap_source mmap;
-mmap.map(path, offset, size_to_map, error);
+mmap.map(path, offset, size_to_map);
 ```
-or:
-```c++
-mmap.map(path, error);
-```
-**NOTE:** The constructors **require** exceptions to be enabled. If you prefer
-to build your projects with `-fno-exceptions`, you can still use the other ways.
 
-Moreover, in each case, you can provide either some string type for the file's path, or you can use an existing, valid file handle.
+Or simply map the entire file:
+
+```c++
+mmap.map(path);
+```
+
+**Important:** All these APIs now use exceptions for error reporting. Internally, error codes are still used, but they are hidden from the external interface.
+
+Moreover, you may provide either a file path (as any common string type) or an existing valid file handle. For example:
+
 ```c++
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <mio/mmap.hpp>
-// #include <mio/mio.hpp> if using single header
 #include <algorithm>
 
-int main()
-{
-    // NOTE: error handling omitted for brevity.
+int main() {
+    // Ensure the file exists before mapping.
     const int fd = open("file.txt", O_RDONLY);
     mio::mmap_source mmap(fd, 0, mio::map_entire_file);
     // ...
 }
 ```
-However, mio does not check whether the provided file descriptor has the same access permissions as the desired mapping, so the mapping may fail. Such errors are reported via the `std::error_code` out parameter that is passed to the mapping function.
 
-**WINDOWS USERS**: This library *does* support the use of wide character types
-for functions where character strings are expected (e.g. path parameters).
+**Windows Users:** Wide character types are supported for path parameters.
+
+---
 
 ### Example
 
+Below is a sample program that demonstrates both read-write and read-only mappings. Notice that no error code parameters are needed—the APIs throw exceptions upon failure.
+
 ```c++
 #include <mio/mmap.hpp>
-// #include <mio/mio.hpp> if using single header
-#include <system_error> // for std::error_code
-#include <cstdio> // for std::printf
+#include <cstdio>
 #include <cassert>
 #include <algorithm>
 #include <fstream>
+#include <iostream>
 
-int handle_error(const std::error_code& error);
-void allocate_file(const std::string& path, const int size);
+void allocate_file(const std::string& path, int size) {
+    std::ofstream file(path);
+    file << std::string(size, '0');
+}
 
-int main()
-{
-    const auto path = "file.txt";
-
-    // NOTE: mio does *not* create the file for you if it doesn't exist! You
-    // must ensure that the file exists before establishing a mapping. It
-    // must also be non-empty. So for illustrative purposes the file is
-    // created now.
+int main() {
+    const std::string path = "file.txt";
     allocate_file(path, 155);
 
-    // Read-write memory map the whole file by using `map_entire_file` where the
-    // length of the mapping is otherwise expected, with the factory method.
-    std::error_code error;
-    mio::mmap_sink rw_mmap = mio::make_mmap_sink(
-            path, 0, mio::map_entire_file, error);
-    if (error) { return handle_error(error); }
+    // Create a read-write mapping for the entire file.
+    mio::mmap_sink rw_mmap = mio::make_mmap_sink(path, 0, mio::map_entire_file);
 
-    // You can use any iterator based function.
+    // Fill the mapping with 'a' characters.
     std::fill(rw_mmap.begin(), rw_mmap.end(), 'a');
 
-    // Or manually iterate through the mapped region just as if it were any other 
-    // container, and change each byte's value (since this is a read-write mapping).
+    // Modify each byte.
     for (auto& b : rw_mmap) {
         b += 10;
     }
 
-    // Or just change one value with the subscript operator.
-    const int answer_index = rw_mmap.size() / 2;
-    rw_mmap[answer_index] = 42;
+    // Change a single byte in the middle.
+    const int mid = rw_mmap.size() / 2;
+    rw_mmap[mid] = 42;
 
-    // Don't forget to flush changes to disk before unmapping. However, if
-    // `rw_mmap` were to go out of scope at this point, the destructor would also
-    // automatically invoke `sync` before `unmap`.
-    rw_mmap.sync(error);
-    if (error) { return handle_error(error); }
-
-    // We can then remove the mapping, after which rw_mmap will be in a default
-    // constructed state, i.e. this and the above call to `sync` have the same
-    // effect as if the destructor had been invoked.
+    // Flush changes and unmap. If the mapping goes out of scope, the destructor will also flush.
+    rw_mmap.sync();
     rw_mmap.unmap();
 
-    // Now create the same mapping, but in read-only mode. Note that calling the
-    // overload without the offset and file length parameters maps the entire
-    // file.
+    // Create a read-only mapping of the entire file.
     mio::mmap_source ro_mmap;
-    ro_mmap.map(path, error);
-    if (error) { return handle_error(error); }
+    ro_mmap.map(path);
 
-    const int the_answer_to_everything = ro_mmap[answer_index];
-    assert(the_answer_to_everything == 42);
+    // Verify that the modification was successful.
+    assert(ro_mmap[mid] == 42);
+
+    std::printf("All tests passed!\n");
+    return 0;
 }
+```
 
-int handle_error(const std::error_code& error)
-{
-    const auto& errmsg = error.message();
-    std::printf("error mapping file: %s, exiting...\n", errmsg.c_str());
-    return error.value();
+---
+
+### Additional Features
+
+This version of `mio` takes advantage of modern C++ features:
+
+- **Source Location and Filesystem:**  
+  Debugging is improved by leveraging `std::source_location` to report detailed context (file name, function name, line, and column) when assertions fail. Filesystem support now enables more natural path handling.
+  
+- **Future C++23 Support:**  
+  In C++23 and above, assertions will include a full stack trace using `std::stacktrace`, making it easier to trace runtime errors.
+
+For example, the new assertion function might look like:
+
+```c++
+#if __cplusplus >= 202002L
+inline void cpp2020_assert(bool condition, const char* errorMessage,
+                             std::source_location location = std::source_location::current()) {
+    if (!condition) {
+        std::cout << "Error: " << errorMessage << "\n"
+                  << "File: " << location.file_name() << "\n"
+                  << "Function: " << location.function_name() << "\n"
+                  << "Line: " << location.line() << "\n"
+                  << "Column: " << location.column() << std::endl;
+#if __cplusplus >= 202300L
+        std::cout << "Stack trace:\n";
+        for (const auto& frame : std::stacktrace::current())
+            std::cout << frame << std::endl;
+#endif
+        throw std::runtime_error(errorMessage);
+    }
 }
+#endif
+```
 
-void allocate_file(const std::string& path, const int size)
+---
+
+### Test Suite Overview
+
+The test suite now combines both the new features and the core mapping functionality. It demonstrates:
+
+- Mapping an entire file or a portion of it.
+- Both read-write and read-only mappings.
+- Mapping with a file descriptor as well as a file path.
+- Validation of mapped content against expected data.
+- Handling of invalid mapping cases without exposing internal error codes.
+
+For example, one test case maps the file at various offsets to verify that the correct segment of the file is mapped:
+
+```c++
+void test_at_offset(const std::string& buffer, const char* path, size_t offset) {
+    // Map the file region starting at the given offset.
+    mio::mmap_source file_view = mio::make_mmap_source(path, offset, mio::map_entire_file);
+    assert(file_view.is_open());
+    // Compare the mapped content to the original buffer...
+}
+```
+
+This comprehensive test case confirms that the modernized `mio` library is robust and adheres to modern C++ best practices.
+
+### Test Suite
+
+The test code below serves a dual purpose. It demonstrates the standard usage of the library (mapping, reading, writing, and unmapping files) while also showcasing intentional error cases. In the error cases, invalid inputs (such as an invalid file path, empty path, or incorrect file handle) will trigger internal assertion exceptions. This change highlights that internal error checking no longer uses `std::error_code` in the public API.
+
+```c++
+#include <string>
+#include <fstream>
+#include <iostream>
+#include <cassert>
+#include <numeric>
+#include <vector>
+
+#include "../single_include/mio/mio.hpp"
+
+// Just make sure this compiles.
+#include <cstddef>
+using mmap_source = mio::basic_mmap_source<std::byte>;
+
+template<class MMap>
+void test_at_offset(const MMap& file_view, const std::string& buffer, const size_t offset);
+inline void test_at_offset(const std::string& buffer, const char* path, const size_t offset);
+
+inline void allocate_file(const std::string& path, const int size)
 {
     std::ofstream file(path);
     std::string s(size, '0');
     file << s;
 }
+
+inline void test_rewrite_file()
+{
+    const auto path = "test_rewrite.txt";
+
+    // NOTE: mio does *not* create the file for you if it doesn't exist!
+    // You must ensure that the file exists and is non-empty before mapping.
+    allocate_file(path, 204800);
+
+    // Create a read-write mapping for the entire file.
+    mio::mmap_sink rw_mmap = mio::make_mmap_sink(
+        path, 0, mio::map_entire_file);
+
+    // Use any iterator-based function to modify the mapping.
+    std::fill(rw_mmap.begin(), rw_mmap.end(), 'a');
+
+    // Or manually iterate through the mapped region and change each byte.
+    for (auto& b : rw_mmap)
+    {
+        b += 10;
+    }
+
+    // Change one specific byte using the subscript operator.
+    const int answer_index = rw_mmap.size() / 2;
+    rw_mmap[answer_index] = 42;
+
+    // Flush changes and unmap.
+    rw_mmap.sync();
+    rw_mmap.unmap();
+
+    // Create a read-only mapping for the entire file.
+    mio::mmap_source ro_mmap;
+    ro_mmap.map(path);
+
+    const int the_answer_to_everything = ro_mmap[answer_index];
+    assert(the_answer_to_everything == 42);
+}
+
+inline void test_error_case(char* path, const std::string& buffer)
+{
+    // Macro to check that an invalid mapping results in an empty mapping.
+#define CHECK_INVALID_MMAP(m) do { \
+        assert(m.empty()); \
+        assert(!m.is_open()); \
+        } while(0)
+
+    mio::mmap_source m;
+
+    // Attempt mapping an invalid file name.
+    m = mio::make_mmap_source("garbage-that-hopefully-doesnt-exist", 0, 0);
+    CHECK_INVALID_MMAP(m);
+
+    // Attempt mapping with an empty path.
+    m = mio::make_mmap_source(static_cast<const char*>(0), 0, 0);
+    CHECK_INVALID_MMAP(m);
+    m = mio::make_mmap_source(std::string(), 0, 0);
+    CHECK_INVALID_MMAP(m);
+
+    // Attempt mapping with an invalid handle.
+    m = mio::make_mmap_source(mio::invalid_handle, 0, 0);
+    CHECK_INVALID_MMAP(m);
+
+    // Attempt mapping with an invalid offset.
+    m = mio::make_mmap_source(path, 100 * buffer.size(), buffer.size());
+    CHECK_INVALID_MMAP(m);
+}
+
+int main()
+{
+    std::system("chcp 65001");
+
+    // Verify that mio compiles with non-const char* strings too.
+    const char _path[] = "test-file";
+    const int path_len = sizeof(_path);
+    char* path = new char[path_len];
+    std::copy(_path, _path + path_len, path);
+
+    const auto page_size = mio::page_size();
+    // Prepare a buffer and write it to a file.
+    const int file_size = 4 * page_size - 250; // For example, 16134 bytes for a 4KiB page size.
+    std::string buffer(file_size, 0);
+    // Fill buffer starting at the first printable ASCII character.
+    char v = 33;
+    for (auto& b : buffer) {
+        b = v;
+        ++v;
+        // Cycle back after reaching the last printable ASCII character.
+        v %= 126;
+        if (v == 0) {
+            v = 33;
+        }
+    }
+
+    std::ofstream file(path);
+    file << buffer;
+    file.close();
+
+    // Test mapping the whole file.
+    test_at_offset(buffer, path, 0);
+
+    // Test mapping starting from an offset just below the page size.
+    test_at_offset(buffer, path, page_size - 3);
+
+    // Test mapping starting from an offset just above the page size.
+    test_at_offset(buffer, path, page_size + 3);
+
+    // Test mapping starting from an offset further ahead.
+    test_at_offset(buffer, path, 2 * page_size + 3);
+
+    std::cout << "Continuing with tests..." << std::endl;
+
+    // Uncomment the next line to run tests for error cases.
+    // Note: In these cases, the internal assertion exceptions will be thrown.
+    // test_error_case(path, buffer);
+
+    // The following code ensures that all API variations compile correctly.
+    {
+        mio::ummap_source _1;
+        mio::shared_ummap_source _2;
+        // shared_mmap mapping compiles as well.
+        mio::shared_mmap_source _3(path, 0, mio::map_entire_file);
+        auto _4 = mio::make_mmap_source(path);
+        auto _5 = mio::make_mmap<mio::shared_mmap_source>(path, 0, mio::map_entire_file);
+#ifdef _WIN32
+        const std::wstring wpath1 = L"file";
+
+        // If the file exists, perform mapping.
+        if (std::filesystem::exists(wpath1))
+        {
+            auto _6 = mio::make_mmap_source(wpath1);
+            mio::mmap_source _7;
+            _7.map(wpath1);
+        }
+        else
+        {
+            std::wcerr << L"Cannot open file: " << wpath1 << std::endl;
+        }
+
+        // Even if the file cannot be opened, the following lines are executed.
+        const std::wstring wpath2 = wpath1 + L"000";
+        if (std::filesystem::exists(wpath2))
+        {
+            auto _8 = mio::make_mmap_source(wpath2);
+            mio::mmap_source _9;
+            _9.map(wpath1);
+        }
+        else
+        {
+            std::wcerr << L"Cannot open file: " << wpath2 << std::endl;
+        }
+#else
+        const char* path = "path_to_file";  // Replace with an actual file path
+        const int fd = open(path, O_RDONLY);
+
+        if (fd < 0)
+        {
+            std::cerr << "Failed to open file: " << path << std::endl;
+        }
+        else
+        {
+            // File opened successfully; perform mmap operations.
+            mio::mmap_source _fdmmap(fd, 0, mio::map_entire_file);
+            // Unmap if needed.
+            _fdmmap.unmap();
+            // Remap using the same file descriptor.
+            _fdmmap.map(fd);
+
+            // Close the file descriptor if it's no longer needed.
+            close(fd);
+        }
+#endif
+    }
+
+    std::printf("all tests passed!\n");
+    return 0;
+}
+
+void test_at_offset(const std::string& buffer, const char* path, const size_t offset)
+{
+    // Sanity check.
+    assert(offset < buffer.size());
+
+    // Map the region of the file starting at the given offset.
+    mio::mmap_source file_view = mio::make_mmap_source(path, offset, mio::map_entire_file);
+
+    assert(file_view.is_open());
+    const size_t mapped_size = buffer.size() - offset;
+    assert(file_view.size() == mapped_size);
+
+    test_at_offset(file_view, buffer, offset);
+
+    // Convert the mapping to a shared mmap.
+    mio::shared_mmap_source shared_file_view(std::move(file_view));
+    assert(!file_view.is_open());
+    assert(shared_file_view.is_open());
+    assert(shared_file_view.size() == mapped_size);
+
+    // Optionally, you can run the test on the shared mapping as well.
+    // test_at_offset(shared_file_view, buffer, offset);
+}
+
+template<class MMap>
+void test_at_offset(const MMap& file_view, const std::string& buffer, const size_t offset)
+{
+    // Verify that the bytes in the mapping match those in the buffer.
+    for (size_t buf_idx = offset, view_idx = 0;
+         buf_idx < buffer.size() && view_idx < file_view.size();
+         ++buf_idx, ++view_idx)
+    {
+        if (file_view[view_idx] != buffer[buf_idx])
+        {
+            std::printf("%luth byte mismatch: expected(%d) <> actual(%d)",
+                        buf_idx, buffer[buf_idx], file_view[view_idx]);
+            std::cout << std::flush;
+            assert(0);
+        }
+    }
+}
 ```
 
-`mio::basic_mmap` is move-only, but if multiple copies to the same mapping are needed, use `mio::basic_shared_mmap` which has `std::shared_ptr` semantics and has the same interface as `mio::basic_mmap`.
 ```c++
-#include <mio/shared_mmap.hpp>
+#include <random>
+#include <iomanip>
+#include <iostream>
+#include <cassert>
+#include <cstddef>
+#include <string>
 
-mio::shared_mmap_source shared_mmap1("path", offset, size_to_map);
-mio::shared_mmap_source shared_mmap2(std::move(mmap1)); // or use operator=
-mio::shared_mmap_source shared_mmap3(std::make_shared<mio::mmap_source>(mmap1)); // or use operator=
-mio::shared_mmap_source shared_mmap4;
-shared_mmap4.map("path", offset, size_to_map, error);
+// Make sure to include your mio header.
+#include "../single_include/mio/mio.hpp"
+
+inline void test_rewrite_random_file()
+{
+	const auto path = "test_rewrite_random.dat";
+
+	// Ensure the file exists and is non-empty.
+	// 20MB = 20971520 Bytes
+	allocate_file(path, 20971520);
+
+	// Seed the random number generator.
+	std::random_device rd;
+	std::mt19937 gen(rd());
+	std::uniform_int_distribution<> dis(0, 255);
+
+	// Create a read-write mapping for the entire file.
+	mio::mmap_sink rw_mmap = mio::make_mmap_sink(path, 0, mio::map_entire_file);
+
+	// Fill the mapping with random binary bytes.
+	for (auto& byte : rw_mmap)
+	{
+		byte = static_cast<char>(dis(gen));
+	}
+
+	// Choose an offset near the end (e.g., 75% into the file) and write the value 42.
+	const size_t answer_index = rw_mmap.size() * 3 / 4;
+	rw_mmap[answer_index] = static_cast<char>(42);
+
+	// Flush changes and unmap.
+	rw_mmap.sync();
+	rw_mmap.unmap();
+
+	// Reopen the file as a read-only mapping.
+	mio::mmap_source ro_mmap;
+	ro_mmap.map(path);
+
+	// Verify that the byte at the chosen offset is 42.
+	const int the_answer = static_cast<int>(ro_mmap[answer_index]);
+	assert(the_answer == 42);
+
+	// Print the entire file content in hexadecimal format.
+	std::cout << "Hex dump of " << path << ":\n";
+	for (size_t i = 0; i < ro_mmap.size(); ++i)
+	{
+		//last 10240 bytes are printed in one line
+		if (ro_mmap.size() - 1 - i < 10240)
+		{
+			std::cout << std::hex << std::setw(2) << std::setfill('0')
+				<< static_cast<int>(static_cast<unsigned char>(ro_mmap[i])) << " ";
+			if ((i + 1) % 16 == 0)
+				std::cout << "\n";
+		}
+	}
+	std::cout << std::dec << "\n"; // Restore default number format.
+}
+
+int main()
+{
+    test_rewrite_random_file();
+}
 ```
 
-It's possible to define the type of a byte (which has to be the same width as `char`), though aliases for the most common ones are provided by default:
+---
+
+### Key Points
+
+- **Error Handling via Exceptions:**  
+  The revised API now uses internal assertions that throw exceptions when encountering errors. This design change replaces the previous use of `std::error_code` in the public API. In the test cases, mapping failures (for example, due to an invalid path) trigger these assertion exceptions.  
+
+- **Demonstrated Error Cases:**  
+  The `test_error_case` function illustrates various invalid inputs (non-existent files, empty paths, invalid handles, and incorrect offsets). These cases are now shown explicitly to guide developers on how the library responds to erroneous usage. (By default, these tests are commented out to avoid interrupting the normal flow; they can be enabled for debugging.)
+
+- **Modern C++ Features:**  
+  The test suite (along with the rest of the library) leverages modern C++ features such as source location for better debug messages. Future updates may also incorporate stack traces when using C++23 or later.
+
+---
+
+### Single Header File
+
+`mio` can be added to your project as a single header file by including:
+
 ```c++
-using mmap_source = basic_mmap_source<char>;
-using ummap_source = basic_mmap_source<unsigned char>;
-
-using mmap_sink = basic_mmap_sink<char>;
-using ummap_sink = basic_mmap_sink<unsigned char>;
-```
-But it may be useful to define your own types, say when using the new `std::byte` type in C++17:
-```c++
-using mmap_source = mio::basic_mmap_source<std::byte>;
-using mmap_sink = mio::basic_mmap_sink<std::byte>;
-```
-
-Though generally not needed, since mio maps users requested offsets to page boundaries, you can query the underlying system's page allocation granularity by invoking `mio::page_size()`, which is located in `mio/page.hpp`.
-
-### Single Header File 
-Mio can be added to your project as a single header file simply by including `\single_include\mio\mio.hpp`. Single header files can be regenerated at any time by running the `amalgamate.py` script within `\third_party`.  
-```
-python amalgamate.py -c config.json -s ../include
+#include "single_include/mio/mio.hpp"
 ```
 
 ## CMake

cmake/CTestCustom.cmake

@@ -1,3 +0,0 @@
-set(CTEST_CUSTOM_COVERAGE_EXCLUDE
-  ".*test.*"
-  ".*c[+][+].*")

cmake/mio-config.cmake.in

@@ -1,13 +0,0 @@
-include(CMakeDependentOption)
-
-CMAKE_DEPENDENT_OPTION(mio.windows.full_api
-  "Configure mio without WIN32_LEAN_AND_MEAN and NOMINMAX definitions"
-  @mio.windows.full_api@ "WIN32" ON)
-
-include("${CMAKE_CURRENT_LIST_DIR}/mio-targets.cmake")
-
-if(NOT mio.windows.full_api)
-  set_property(TARGET mio::mio APPEND PROPERTY INTERFACE_COMPILE_DEFINITIONS
-    WIN32_LEAN_AND_MEAN
-    NOMINMAX)
-endif()

include/mio/CMakeLists.txt

@@ -1,11 +0,0 @@
-#
-# While not strictly necessary to specify header files as target sources,
-# doing so populates these files in the source listing when CMake is used
-# to generate XCode and Visual Studios projects
-#
-target_sources(mio-headers INTERFACE
-  "${prefix}/mio/mmap.hpp"
-  "${prefix}/mio/page.hpp"
-  "${prefix}/mio/shared_mmap.hpp")
-
-add_subdirectory(detail)

include/mio/detail/CMakeLists.txt

@@ -1,3 +0,0 @@
-target_sources(mio-headers INTERFACE
-  "${prefix}/mio/detail/mmap.ipp"
-  "${prefix}/mio/detail/string_util.hpp")

include/mio/detail/mmap.ipp

@@ -1,530 +0,0 @@
-/* Copyright 2017 https://github.com/mandreyel
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this
- * software and associated documentation files (the "Software"), to deal in the Software
- * without restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies
- * or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
- * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef MIO_BASIC_MMAP_IMPL
-#define MIO_BASIC_MMAP_IMPL
-
-#include "mio/mmap.hpp"
-#include "mio/page.hpp"
-#include "mio/detail/string_util.hpp"
-
-#include <algorithm>
-
-#ifndef _WIN32
-# include <unistd.h>
-# include <fcntl.h>
-# include <sys/mman.h>
-# include <sys/stat.h>
-#endif
-
-namespace mio {
-namespace detail {
-
-#ifdef _WIN32
-namespace win {
-
-/** Returns the 4 upper bytes of an 8-byte integer. */
-inline DWORD int64_high(int64_t n) noexcept
-{
-    return n >> 32;
-}
-
-/** Returns the 4 lower bytes of an 8-byte integer. */
-inline DWORD int64_low(int64_t n) noexcept
-{
-    return n & 0xffffffff;
-}
-
-std::wstring s_2_ws(const std::string& s)
-{
-    if (s.empty())
-        return{};
-    const auto s_length = static_cast<int>(s.length());
-    auto buf = std::vector<wchar_t>(s_length);
-    const auto wide_char_count = MultiByteToWideChar(CP_UTF8, 0, s.c_str(), s_length, buf.data(), s_length);
-    return std::wstring(buf.data(), wide_char_count);
-}
-
-template<
-    typename String,
-    typename = typename std::enable_if<
-        std::is_same<typename char_type<String>::type, char>::value
-    >::type
-> file_handle_type open_file_helper(const String& path, const access_mode mode)
-{
-    return ::CreateFileW(s_2_ws(path).c_str(),
-            mode == access_mode::read ? GENERIC_READ : GENERIC_READ | GENERIC_WRITE,
-            FILE_SHARE_READ | FILE_SHARE_WRITE,
-            0,
-            OPEN_EXISTING,
-            FILE_ATTRIBUTE_NORMAL,
-            0);
-}
-
-template<typename String>
-typename std::enable_if<
-    std::is_same<typename char_type<String>::type, wchar_t>::value,
-    file_handle_type
->::type open_file_helper(const String& path, const access_mode mode)
-{
-    return ::CreateFileW(c_str(path),
-            mode == access_mode::read ? GENERIC_READ : GENERIC_READ | GENERIC_WRITE,
-            FILE_SHARE_READ | FILE_SHARE_WRITE,
-            0,
-            OPEN_EXISTING,
-            FILE_ATTRIBUTE_NORMAL,
-            0);
-}
-
-} // win
-#endif // _WIN32
-
-/**
- * Returns the last platform specific system error (errno on POSIX and
- * GetLastError on Win) as a `std::error_code`.
- */
-inline std::error_code last_error() noexcept
-{
-    std::error_code error;
-#ifdef _WIN32
-    error.assign(GetLastError(), std::system_category());
-#else
-    error.assign(errno, std::system_category());
-#endif
-    return error;
-}
-
-template<typename String>
-file_handle_type open_file(const String& path, const access_mode mode,
-        std::error_code& error)
-{
-    error.clear();
-    if(detail::empty(path))
-    {
-        error = std::make_error_code(std::errc::invalid_argument);
-        return invalid_handle;
-    }
-#ifdef _WIN32
-    const auto handle = win::open_file_helper(path, mode);
-#else // POSIX
-    const auto handle = ::open(c_str(path),
-            mode == access_mode::read ? O_RDONLY : O_RDWR);
-#endif
-    if(handle == invalid_handle)
-    {
-        error = detail::last_error();
-    }
-    return handle;
-}
-
-inline size_t query_file_size(file_handle_type handle, std::error_code& error)
-{
-    error.clear();
-#ifdef _WIN32
-    LARGE_INTEGER file_size;
-    if(::GetFileSizeEx(handle, &file_size) == 0)
-    {
-        error = detail::last_error();
-        return 0;
-    }
-	return static_cast<int64_t>(file_size.QuadPart);
-#else // POSIX
-    struct stat sbuf;
-    if(::fstat(handle, &sbuf) == -1)
-    {
-        error = detail::last_error();
-        return 0;
-    }
-    return sbuf.st_size;
-#endif
-}
-
-struct mmap_context
-{
-    char* data;
-    int64_t length;
-    int64_t mapped_length;
-#ifdef _WIN32
-    file_handle_type file_mapping_handle;
-#endif
-};
-
-inline mmap_context memory_map(const file_handle_type file_handle, const int64_t offset,
-    const int64_t length, const access_mode mode, std::error_code& error)
-{
-    const int64_t aligned_offset = make_offset_page_aligned(offset);
-    const int64_t length_to_map = offset - aligned_offset + length;
-#ifdef _WIN32
-    const int64_t max_file_size = offset + length;
-    const auto file_mapping_handle = ::CreateFileMapping(
-            file_handle,
-            0,
-            mode == access_mode::read ? PAGE_READONLY : PAGE_READWRITE,
-            win::int64_high(max_file_size),
-            win::int64_low(max_file_size),
-            0);
-    if(file_mapping_handle == invalid_handle)
-    {
-        error = detail::last_error();
-        return {};
-    }
-    char* mapping_start = static_cast<char*>(::MapViewOfFile(
-            file_mapping_handle,
-            mode == access_mode::read ? FILE_MAP_READ : FILE_MAP_WRITE,
-            win::int64_high(aligned_offset),
-            win::int64_low(aligned_offset),
-            length_to_map));
-    if(mapping_start == nullptr)
-    {
-        // Close file handle if mapping it failed.
-        ::CloseHandle(file_mapping_handle);
-        error = detail::last_error();
-        return {};
-    }
-#else // POSIX
-    char* mapping_start = static_cast<char*>(::mmap(
-            0, // Don't give hint as to where to map.
-            length_to_map,
-            mode == access_mode::read ? PROT_READ : PROT_WRITE,
-            MAP_SHARED,
-            file_handle,
-            aligned_offset));
-    if(mapping_start == MAP_FAILED)
-    {
-        error = detail::last_error();
-        return {};
-    }
-#endif
-    mmap_context ctx;
-    ctx.data = mapping_start + offset - aligned_offset;
-    ctx.length = length;
-    ctx.mapped_length = length_to_map;
-#ifdef _WIN32
-    ctx.file_mapping_handle = file_mapping_handle;
-#endif
-    return ctx;
-}
-
-} // namespace detail
-
-// -- basic_mmap --
-
-template<access_mode AccessMode, typename ByteT>
-basic_mmap<AccessMode, ByteT>::~basic_mmap()
-{
-    conditional_sync();
-    unmap();
-}
-
-template<access_mode AccessMode, typename ByteT>
-basic_mmap<AccessMode, ByteT>::basic_mmap(basic_mmap&& other)
-    : data_(std::move(other.data_))
-    , length_(std::move(other.length_))
-    , mapped_length_(std::move(other.mapped_length_))
-    , file_handle_(std::move(other.file_handle_))
-#ifdef _WIN32
-    , file_mapping_handle_(std::move(other.file_mapping_handle_))
-#endif
-    , is_handle_internal_(std::move(other.is_handle_internal_))
-{
-    other.data_ = nullptr;
-    other.length_ = other.mapped_length_ = 0;
-    other.file_handle_ = invalid_handle;
-#ifdef _WIN32
-    other.file_mapping_handle_ = invalid_handle;
-#endif
-}
-
-template<access_mode AccessMode, typename ByteT>
-basic_mmap<AccessMode, ByteT>&
-basic_mmap<AccessMode, ByteT>::operator=(basic_mmap&& other)
-{
-    if(this != &other)
-    {
-        // First the existing mapping needs to be removed.
-        unmap();
-        data_ = std::move(other.data_);
-        length_ = std::move(other.length_);
-        mapped_length_ = std::move(other.mapped_length_);
-        file_handle_ = std::move(other.file_handle_);
-#ifdef _WIN32
-        file_mapping_handle_ = std::move(other.file_mapping_handle_);
-#endif
-        is_handle_internal_ = std::move(other.is_handle_internal_);
-
-        // The moved from basic_mmap's fields need to be reset, because
-        // otherwise other's destructor will unmap the same mapping that was
-        // just moved into this.
-        other.data_ = nullptr;
-        other.length_ = other.mapped_length_ = 0;
-        other.file_handle_ = invalid_handle;
-#ifdef _WIN32
-        other.file_mapping_handle_ = invalid_handle;
-#endif
-        other.is_handle_internal_ = false;
-    }
-    return *this;
-}
-
-template<access_mode AccessMode, typename ByteT>
-typename basic_mmap<AccessMode, ByteT>::handle_type
-basic_mmap<AccessMode, ByteT>::mapping_handle() const noexcept
-{
-#ifdef _WIN32
-    return file_mapping_handle_;
-#else
-    return file_handle_;
-#endif
-}
-
-template<access_mode AccessMode, typename ByteT>
-template<typename String>
-void basic_mmap<AccessMode, ByteT>::map(const String& path, const size_type offset,
-        const size_type length, std::error_code& error)
-{
-    error.clear();
-    if(detail::empty(path))
-    {
-        error = std::make_error_code(std::errc::invalid_argument);
-        return;
-    }
-    const auto handle = detail::open_file(path, AccessMode, error);
-    if(error)
-    {
-        return;
-    }
-
-    map(handle, offset, length, error);
-    // This MUST be after the call to map, as that sets this to true.
-    if(!error)
-    {
-        is_handle_internal_ = true;
-    }
-}
-
-template<access_mode AccessMode, typename ByteT>
-void basic_mmap<AccessMode, ByteT>::map(const handle_type handle,
-        const size_type offset, const size_type length, std::error_code& error)
-{
-    error.clear();
-    if(handle == invalid_handle)
-    {
-        error = std::make_error_code(std::errc::bad_file_descriptor);
-        return;
-    }
-
-    const auto file_size = detail::query_file_size(handle, error);
-    if(error)
-    {
-        return;
-    }
-
-    if(offset + length > file_size)
-    {
-        error = std::make_error_code(std::errc::invalid_argument);
-        return;
-    }
-
-    const auto ctx = detail::memory_map(handle, offset,
-            length == map_entire_file ? (file_size - offset) : length,
-            AccessMode, error);
-    if(!error)
-    {
-        // We must unmap the previous mapping that may have existed prior to this call.
-        // Note that this must only be invoked after a new mapping has been created in
-        // order to provide the strong guarantee that, should the new mapping fail, the
-        // `map` function leaves this instance in a state as though the function had
-        // never been invoked.
-        unmap();
-        file_handle_ = handle;
-        is_handle_internal_ = false;
-        data_ = reinterpret_cast<pointer>(ctx.data);
-        length_ = ctx.length;
-        mapped_length_ = ctx.mapped_length;
-#ifdef _WIN32
-        file_mapping_handle_ = ctx.file_mapping_handle;
-#endif
-    }
-}
-
-template<access_mode AccessMode, typename ByteT>
-template<access_mode A>
-typename std::enable_if<A == access_mode::write, void>::type
-basic_mmap<AccessMode, ByteT>::sync(std::error_code& error)
-{
-    error.clear();
-    if(!is_open())
-    {
-        error = std::make_error_code(std::errc::bad_file_descriptor);
-        return;
-    }
-
-    if(data())
-    {
-#ifdef _WIN32
-        if(::FlushViewOfFile(get_mapping_start(), mapped_length_) == 0
-           || ::FlushFileBuffers(file_handle_) == 0)
-#else // POSIX
-        if(::msync(get_mapping_start(), mapped_length_, MS_SYNC) != 0)
-#endif
-        {
-            error = detail::last_error();
-            return;
-        }
-    }
-#ifdef _WIN32
-    if(::FlushFileBuffers(file_handle_) == 0)
-    {
-        error = detail::last_error();
-    }
-#endif
-}
-
-template<access_mode AccessMode, typename ByteT>
-void basic_mmap<AccessMode, ByteT>::unmap()
-{
-    if(!is_open()) { return; }
-    // TODO do we care about errors here?
-#ifdef _WIN32
-    if(is_mapped())
-    {
-        ::UnmapViewOfFile(get_mapping_start());
-        ::CloseHandle(file_mapping_handle_);
-    }
-#else // POSIX
-    if(data_) { ::munmap(const_cast<pointer>(get_mapping_start()), mapped_length_); }
-#endif
-
-    // If `file_handle_` was obtained by our opening it (when map is called with
-    // a path, rather than an existing file handle), we need to close it,
-    // otherwise it must not be closed as it may still be used outside this
-    // instance.
-    if(is_handle_internal_)
-    {
-#ifdef _WIN32
-        ::CloseHandle(file_handle_);
-#else // POSIX
-        ::close(file_handle_);
-#endif
-    }
-
-    // Reset fields to their default values.
-    data_ = nullptr;
-    length_ = mapped_length_ = 0;
-    file_handle_ = invalid_handle;
-#ifdef _WIN32
-    file_mapping_handle_ = invalid_handle;
-#endif
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool basic_mmap<AccessMode, ByteT>::is_mapped() const noexcept
-{
-#ifdef _WIN32
-    return file_mapping_handle_ != invalid_handle;
-#else // POSIX
-    return is_open();
-#endif
-}
-
-template<access_mode AccessMode, typename ByteT>
-void basic_mmap<AccessMode, ByteT>::swap(basic_mmap& other)
-{
-    if(this != &other)
-    {
-        using std::swap;
-        swap(data_, other.data_);
-        swap(file_handle_, other.file_handle_);
-#ifdef _WIN32
-        swap(file_mapping_handle_, other.file_mapping_handle_);
-#endif
-        swap(length_, other.length_);
-        swap(mapped_length_, other.mapped_length_);
-        swap(is_handle_internal_, other.is_handle_internal_);
-    }
-}
-
-template<access_mode AccessMode, typename ByteT>
-template<access_mode A>
-typename std::enable_if<A == access_mode::write, void>::type
-basic_mmap<AccessMode, ByteT>::conditional_sync()
-{
-    // This is invoked from the destructor, so not much we can do about
-    // failures here.
-    std::error_code ec;
-    sync(ec);
-}
-
-template<access_mode AccessMode, typename ByteT>
-template<access_mode A>
-typename std::enable_if<A == access_mode::read, void>::type
-basic_mmap<AccessMode, ByteT>::conditional_sync()
-{
-    // noop
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator==(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    return a.data() == b.data()
-        && a.size() == b.size();
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator!=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    return !(a == b);
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator<(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    if(a.data() == b.data()) { return a.size() < b.size(); }
-    return a.data() < b.data();
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator<=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    return !(a > b);
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator>(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    if(a.data() == b.data()) { return a.size() > b.size(); }
-    return a.data() > b.data();
-}
-
-template<access_mode AccessMode, typename ByteT>
-bool operator>=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b)
-{
-    return !(a < b);
-}
-
-} // namespace mio
-
-#endif // MIO_BASIC_MMAP_IMPL

include/mio/detail/string_util.hpp

@@ -1,170 +0,0 @@
-/* Copyright 2017 https://github.com/mandreyel
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this
- * software and associated documentation files (the "Software"), to deal in the Software
- * without restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies
- * or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
- * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef MIO_STRING_UTIL_HEADER
-#define MIO_STRING_UTIL_HEADER
-
-#include <type_traits>
-
-namespace mio {
-namespace detail {
-
-template<
-    typename S,
-    typename C = typename std::decay<S>::type,
-    typename = decltype(std::declval<C>().data()),
-    typename = typename std::enable_if<
-        std::is_same<typename C::value_type, char>::value
-#ifdef _WIN32
-        || std::is_same<typename C::value_type, wchar_t>::value
-#endif
-    >::type
-> struct char_type_helper {
-    using type = typename C::value_type;
-};
-
-template<class T>
-struct char_type {
-    using type = typename char_type_helper<T>::type;
-};
-
-// TODO: can we avoid this brute force approach?
-template<>
-struct char_type<char*> {
-    using type = char;
-};
-
-template<>
-struct char_type<const char*> {
-    using type = char;
-};
-
-template<size_t N>
-struct char_type<char[N]> {
-    using type = char;
-};
-
-template<size_t N>
-struct char_type<const char[N]> {
-    using type = char;
-};
-
-#ifdef _WIN32
-template<>
-struct char_type<wchar_t*> {
-    using type = wchar_t;
-};
-
-template<>
-struct char_type<const wchar_t*> {
-    using type = wchar_t;
-};
-
-template<size_t N>
-struct char_type<wchar_t[N]> {
-    using type = wchar_t;
-};
-
-template<size_t N>
-struct char_type<const wchar_t[N]> {
-    using type = wchar_t;
-};
-#endif // _WIN32
-
-template<typename CharT, typename S>
-struct is_c_str_helper
-{
-    static constexpr bool value = std::is_same<
-        CharT*,
-        // TODO: I'm so sorry for this... Can this be made cleaner?
-        typename std::add_pointer<
-            typename std::remove_cv<
-                typename std::remove_pointer<
-                    typename std::decay<
-                        S
-                    >::type
-                >::type
-            >::type
-        >::type
-    >::value;
-};
-
-template<typename S>
-struct is_c_str
-{
-    static constexpr bool value = is_c_str_helper<char, S>::value;
-};
-
-#ifdef _WIN32
-template<typename S>
-struct is_c_wstr
-{
-    static constexpr bool value = is_c_str_helper<wchar_t, S>::value;
-};
-#endif // _WIN32
-
-template<typename S>
-struct is_c_str_or_c_wstr
-{
-    static constexpr bool value = is_c_str<S>::value
-#ifdef _WIN32
-        || is_c_wstr<S>::value
-#endif
-        ;
-};
-
-template<
-    typename String,
-    typename = decltype(std::declval<String>().data()),
-    typename = typename std::enable_if<!is_c_str_or_c_wstr<String>::value>::type
-> const typename char_type<String>::type* c_str(const String& path)
-{
-    return path.data();
-}
-
-template<
-    typename String,
-    typename = decltype(std::declval<String>().empty()),
-    typename = typename std::enable_if<!is_c_str_or_c_wstr<String>::value>::type
-> bool empty(const String& path)
-{
-    return path.empty();
-}
-
-template<
-    typename String,
-    typename = typename std::enable_if<is_c_str_or_c_wstr<String>::value>::type
-> const typename char_type<String>::type* c_str(String path)
-{
-    return path;
-}
-
-template<
-    typename String,
-    typename = typename std::enable_if<is_c_str_or_c_wstr<String>::value>::type
-> bool empty(String path)
-{
-    return !path || (*path == 0);
-}
-
-} // namespace detail
-} // namespace mio
-
-#endif // MIO_STRING_UTIL_HEADER

include/mio/mmap.hpp

@@ -1,492 +0,0 @@
-/* Copyright 2017 https://github.com/mandreyel
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this
- * software and associated documentation files (the "Software"), to deal in the Software
- * without restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies
- * or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
- * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef MIO_MMAP_HEADER
-#define MIO_MMAP_HEADER
-
-#include "mio/page.hpp"
-
-#include <iterator>
-#include <string>
-#include <system_error>
-#include <cstdint>
-
-#ifdef _WIN32
-# ifndef WIN32_LEAN_AND_MEAN
-#  define WIN32_LEAN_AND_MEAN
-# endif // WIN32_LEAN_AND_MEAN
-# include <windows.h>
-#else // ifdef _WIN32
-# define INVALID_HANDLE_VALUE -1
-#endif // ifdef _WIN32
-
-namespace mio {
-
-// This value may be provided as the `length` parameter to the constructor or
-// `map`, in which case a memory mapping of the entire file is created.
-enum { map_entire_file = 0 };
-
-#ifdef _WIN32
-using file_handle_type = HANDLE;
-#else
-using file_handle_type = int;
-#endif
-
-// This value represents an invalid file handle type. This can be used to
-// determine whether `basic_mmap::file_handle` is valid, for example.
-const static file_handle_type invalid_handle = INVALID_HANDLE_VALUE;
-
-template<access_mode AccessMode, typename ByteT>
-struct basic_mmap
-{
-    using value_type = ByteT;
-    using size_type = size_t;
-    using reference = value_type&;
-    using const_reference = const value_type&;
-    using pointer = value_type*;
-    using const_pointer = const value_type*;
-    using difference_type = std::ptrdiff_t;
-    using iterator = pointer;
-    using const_iterator = const_pointer;
-    using reverse_iterator = std::reverse_iterator<iterator>;
-    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
-    using iterator_category = std::random_access_iterator_tag;
-    using handle_type = file_handle_type;
-
-    static_assert(sizeof(ByteT) == sizeof(char), "ByteT must be the same size as char.");
-
-private:
-    // Points to the first requested byte, and not to the actual start of the mapping.
-    pointer data_ = nullptr;
-
-    // Length--in bytes--requested by user (which may not be the length of the
-    // full mapping) and the length of the full mapping.
-    size_type length_ = 0;
-    size_type mapped_length_ = 0;
-
-    // Letting user map a file using both an existing file handle and a path
-    // introcudes some complexity (see `is_handle_internal_`).
-    // On POSIX, we only need a file handle to create a mapping, while on
-    // Windows systems the file handle is necessary to retrieve a file mapping
-    // handle, but any subsequent operations on the mapped region must be done
-    // through the latter.
-    handle_type file_handle_ = INVALID_HANDLE_VALUE;
-#ifdef _WIN32
-    handle_type file_mapping_handle_ = INVALID_HANDLE_VALUE;
-#endif
-
-    // Letting user map a file using both an existing file handle and a path
-    // introcudes some complexity in that we must not close the file handle if
-    // user provided it, but we must close it if we obtained it using the
-    // provided path. For this reason, this flag is used to determine when to
-    // close `file_handle_`.
-    bool is_handle_internal_;
-
-public:
-    /**
-     * The default constructed mmap object is in a non-mapped state, that is,
-     * any operation that attempts to access nonexistent underlying data will
-     * result in undefined behaviour/segmentation faults.
-     */
-    basic_mmap() = default;
-
-#ifdef __cpp_exceptions
-    /**
-     * The same as invoking the `map` function, except any error that may occur
-     * while establishing the mapping is wrapped in a `std::system_error` and is
-     * thrown.
-     */
-    template<typename String>
-    basic_mmap(const String& path, const size_type offset = 0, const size_type length = map_entire_file)
-    {
-        std::error_code error;
-        map(path, offset, length, error);
-        if(error) { throw std::system_error(error); }
-    }
-
-    /**
-     * The same as invoking the `map` function, except any error that may occur
-     * while establishing the mapping is wrapped in a `std::system_error` and is
-     * thrown.
-     */
-    basic_mmap(const handle_type handle, const size_type offset = 0, const size_type length = map_entire_file)
-    {
-        std::error_code error;
-        map(handle, offset, length, error);
-        if(error) { throw std::system_error(error); }
-    }
-#endif // __cpp_exceptions
-
-    /**
-     * `basic_mmap` has single-ownership semantics, so transferring ownership
-     * may only be accomplished by moving the object.
-     */
-    basic_mmap(const basic_mmap&) = delete;
-    basic_mmap(basic_mmap&&);
-    basic_mmap& operator=(const basic_mmap&) = delete;
-    basic_mmap& operator=(basic_mmap&&);
-
-    /**
-     * If this is a read-write mapping, the destructor invokes sync. Regardless
-     * of the access mode, unmap is invoked as a final step.
-     */
-    ~basic_mmap();
-
-    /**
-     * On UNIX systems 'file_handle' and 'mapping_handle' are the same. On Windows,
-     * however, a mapped region of a file gets its own handle, which is returned by
-     * 'mapping_handle'.
-     */
-    handle_type file_handle() const noexcept { return file_handle_; }
-    handle_type mapping_handle() const noexcept;
-
-    /** Returns whether a valid memory mapping has been created. */
-    bool is_open() const noexcept { return file_handle_ != invalid_handle; }
-
-    /**
-     * Returns true if no mapping was established, that is, conceptually the
-     * same as though the length that was mapped was 0. This function is
-     * provided so that this class has Container semantics.
-     */
-    bool empty() const noexcept { return length() == 0; }
-
-    /** Returns true if a mapping was established. */
-    bool is_mapped() const noexcept;
-
-    /**
-     * `size` and `length` both return the logical length, i.e. the number of bytes
-     * user requested to be mapped, while `mapped_length` returns the actual number of
-     * bytes that were mapped which is a multiple of the underlying operating system's
-     * page allocation granularity.
-     */
-    size_type size() const noexcept { return length(); }
-    size_type length() const noexcept { return length_; }
-    size_type mapped_length() const noexcept { return mapped_length_; }
-
-    /** Returns the offset relative to the start of the mapping. */
-    size_type mapping_offset() const noexcept
-    {
-        return mapped_length_ - length_;
-    }
-
-    /**
-     * Returns a pointer to the first requested byte, or `nullptr` if no memory mapping
-     * exists.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > pointer data() noexcept { return data_; }
-    const_pointer data() const noexcept { return data_; }
-
-    /**
-     * Returns an iterator to the first requested byte, if a valid memory mapping
-     * exists, otherwise this function call is undefined behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > iterator begin() noexcept { return data(); }
-    const_iterator begin() const noexcept { return data(); }
-    const_iterator cbegin() const noexcept { return data(); }
-
-    /**
-     * Returns an iterator one past the last requested byte, if a valid memory mapping
-     * exists, otherwise this function call is undefined behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > iterator end() noexcept { return data() + length(); }
-    const_iterator end() const noexcept { return data() + length(); }
-    const_iterator cend() const noexcept { return data() + length(); }
-
-    /**
-     * Returns a reverse iterator to the last memory mapped byte, if a valid
-     * memory mapping exists, otherwise this function call is undefined
-     * behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > reverse_iterator rbegin() noexcept { return reverse_iterator(end()); }
-    const_reverse_iterator rbegin() const noexcept
-    { return const_reverse_iterator(end()); }
-    const_reverse_iterator crbegin() const noexcept
-    { return const_reverse_iterator(end()); }
-
-    /**
-     * Returns a reverse iterator past the first mapped byte, if a valid memory
-     * mapping exists, otherwise this function call is undefined behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > reverse_iterator rend() noexcept { return reverse_iterator(begin()); }
-    const_reverse_iterator rend() const noexcept
-    { return const_reverse_iterator(begin()); }
-    const_reverse_iterator crend() const noexcept
-    { return const_reverse_iterator(begin()); }
-
-    /**
-     * Returns a reference to the `i`th byte from the first requested byte (as returned
-     * by `data`). If this is invoked when no valid memory mapping has been created
-     * prior to this call, undefined behaviour ensues.
-     */
-    reference operator[](const size_type i) noexcept { return data_[i]; }
-    const_reference operator[](const size_type i) const noexcept { return data_[i]; }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `path`, which must be a path to an existing file, is used to retrieve a file
-     * handle (which is closed when the object destructs or `unmap` is called), which is
-     * then used to memory map the requested region. Upon failure, `error` is set to
-     * indicate the reason and the object remains in an unmapped state.
-     *
-     * `offset` is the number of bytes, relative to the start of the file, where the
-     * mapping should begin. When specifying it, there is no need to worry about
-     * providing a value that is aligned with the operating system's page allocation
-     * granularity. This is adjusted by the implementation such that the first requested
-     * byte (as returned by `data` or `begin`), so long as `offset` is valid, will be at
-     * `offset` from the start of the file.
-     *
-     * `length` is the number of bytes to map. It may be `map_entire_file`, in which
-     * case a mapping of the entire file is created.
-     */
-    template<typename String>
-    void map(const String& path, const size_type offset,
-            const size_type length, std::error_code& error);
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `path`, which must be a path to an existing file, is used to retrieve a file
-     * handle (which is closed when the object destructs or `unmap` is called), which is
-     * then used to memory map the requested region. Upon failure, `error` is set to
-     * indicate the reason and the object remains in an unmapped state.
-     * 
-     * The entire file is mapped.
-     */
-    template<typename String>
-    void map(const String& path, std::error_code& error)
-    {
-        map(path, 0, map_entire_file, error);
-    }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is
-     * unsuccesful, the reason is reported via `error` and the object remains in
-     * a state as if this function hadn't been called.
-     *
-     * `handle`, which must be a valid file handle, which is used to memory map the
-     * requested region. Upon failure, `error` is set to indicate the reason and the
-     * object remains in an unmapped state.
-     *
-     * `offset` is the number of bytes, relative to the start of the file, where the
-     * mapping should begin. When specifying it, there is no need to worry about
-     * providing a value that is aligned with the operating system's page allocation
-     * granularity. This is adjusted by the implementation such that the first requested
-     * byte (as returned by `data` or `begin`), so long as `offset` is valid, will be at
-     * `offset` from the start of the file.
-     *
-     * `length` is the number of bytes to map. It may be `map_entire_file`, in which
-     * case a mapping of the entire file is created.
-     */
-    void map(const handle_type handle, const size_type offset,
-            const size_type length, std::error_code& error);
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is
-     * unsuccesful, the reason is reported via `error` and the object remains in
-     * a state as if this function hadn't been called.
-     *
-     * `handle`, which must be a valid file handle, which is used to memory map the
-     * requested region. Upon failure, `error` is set to indicate the reason and the
-     * object remains in an unmapped state.
-     * 
-     * The entire file is mapped.
-     */
-    void map(const handle_type handle, std::error_code& error)
-    {
-        map(handle, 0, map_entire_file, error);
-    }
-
-    /**
-     * If a valid memory mapping has been created prior to this call, this call
-     * instructs the kernel to unmap the memory region and disassociate this object
-     * from the file.
-     *
-     * The file handle associated with the file that is mapped is only closed if the
-     * mapping was created using a file path. If, on the other hand, an existing
-     * file handle was used to create the mapping, the file handle is not closed.
-     */
-    void unmap();
-
-    void swap(basic_mmap& other);
-
-    /** Flushes the memory mapped page to disk. Errors are reported via `error`. */
-    template<access_mode A = AccessMode>
-    typename std::enable_if<A == access_mode::write, void>::type
-    sync(std::error_code& error);
-
-    /**
-     * All operators compare the address of the first byte and size of the two mapped
-     * regions.
-     */
-
-private:
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > pointer get_mapping_start() noexcept
-    {
-        return !data() ? nullptr : data() - mapping_offset();
-    }
-
-    const_pointer get_mapping_start() const noexcept
-    {
-        return !data() ? nullptr : data() - mapping_offset();
-    }
-
-    /**
-     * The destructor syncs changes to disk if `AccessMode` is `write`, but not
-     * if it's `read`, but since the destructor cannot be templated, we need to
-     * do SFINAE in a dedicated function, where one syncs and the other is a noop.
-     */
-    template<access_mode A = AccessMode>
-    typename std::enable_if<A == access_mode::write, void>::type
-    conditional_sync();
-    template<access_mode A = AccessMode>
-    typename std::enable_if<A == access_mode::read, void>::type conditional_sync();
-};
-
-template<access_mode AccessMode, typename ByteT>
-bool operator==(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-template<access_mode AccessMode, typename ByteT>
-bool operator!=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-template<access_mode AccessMode, typename ByteT>
-bool operator<(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-template<access_mode AccessMode, typename ByteT>
-bool operator<=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-template<access_mode AccessMode, typename ByteT>
-bool operator>(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-template<access_mode AccessMode, typename ByteT>
-bool operator>=(const basic_mmap<AccessMode, ByteT>& a,
-        const basic_mmap<AccessMode, ByteT>& b);
-
-/**
- * This is the basis for all read-only mmap objects and should be preferred over
- * directly using `basic_mmap`.
- */
-template<typename ByteT>
-using basic_mmap_source = basic_mmap<access_mode::read, ByteT>;
-
-/**
- * This is the basis for all read-write mmap objects and should be preferred over
- * directly using `basic_mmap`.
- */
-template<typename ByteT>
-using basic_mmap_sink = basic_mmap<access_mode::write, ByteT>;
-
-/**
- * These aliases cover the most common use cases, both representing a raw byte stream
- * (either with a char or an unsigned char/uint8_t).
- */
-using mmap_source = basic_mmap_source<char>;
-using ummap_source = basic_mmap_source<unsigned char>;
-
-using mmap_sink = basic_mmap_sink<char>;
-using ummap_sink = basic_mmap_sink<unsigned char>;
-
-/**
- * Convenience factory method that constructs a mapping for any `basic_mmap` or
- * `basic_mmap` type.
- */
-template<
-    typename MMap,
-    typename MappingToken
-> MMap make_mmap(const MappingToken& token,
-        int64_t offset, int64_t length, std::error_code& error)
-{
-    MMap mmap;
-    mmap.map(token, offset, length, error);
-    return mmap;
-}
-
-/**
- * Convenience factory method.
- *
- * MappingToken may be a String (`std::string`, `std::string_view`, `const char*`,
- * `std::filesystem::path`, `std::vector<char>`, or similar), or a
- * `mmap_source::handle_type`.
- */
-template<typename MappingToken>
-mmap_source make_mmap_source(const MappingToken& token, mmap_source::size_type offset,
-        mmap_source::size_type length, std::error_code& error)
-{
-    return make_mmap<mmap_source>(token, offset, length, error);
-}
-
-template<typename MappingToken>
-mmap_source make_mmap_source(const MappingToken& token, std::error_code& error)
-{
-    return make_mmap_source(token, 0, map_entire_file, error);
-}
-
-/**
- * Convenience factory method.
- *
- * MappingToken may be a String (`std::string`, `std::string_view`, `const char*`,
- * `std::filesystem::path`, `std::vector<char>`, or similar), or a
- * `mmap_sink::handle_type`.
- */
-template<typename MappingToken>
-mmap_sink make_mmap_sink(const MappingToken& token, mmap_sink::size_type offset,
-        mmap_sink::size_type length, std::error_code& error)
-{
-    return make_mmap<mmap_sink>(token, offset, length, error);
-}
-
-template<typename MappingToken>
-mmap_sink make_mmap_sink(const MappingToken& token, std::error_code& error)
-{
-    return make_mmap_sink(token, 0, map_entire_file, error);
-}
-
-} // namespace mio
-
-#include "detail/mmap.ipp"
-
-#endif // MIO_MMAP_HEADER

include/mio/page.hpp

@@ -1,78 +0,0 @@
-/* Copyright 2017 https://github.com/mandreyel
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this
- * software and associated documentation files (the "Software"), to deal in the Software
- * without restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies
- * or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
- * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef MIO_PAGE_HEADER
-#define MIO_PAGE_HEADER
-
-#ifdef _WIN32
-# include <windows.h>
-#else
-# include <unistd.h>
-#endif
-
-namespace mio {
-
-/**
- * This is used by `basic_mmap` to determine whether to create a read-only or
- * a read-write memory mapping.
- */
-enum class access_mode
-{
-    read,
-    write
-};
-
-/**
- * Determines the operating system's page allocation granularity.
- *
- * On the first call to this function, it invokes the operating system specific syscall
- * to determine the page size, caches the value, and returns it. Any subsequent call to
- * this function serves the cached value, so no further syscalls are made.
- */
-inline size_t page_size()
-{
-    static const size_t page_size = []
-    {
-#ifdef _WIN32
-        SYSTEM_INFO SystemInfo;
-        GetSystemInfo(&SystemInfo);
-        return SystemInfo.dwAllocationGranularity;
-#else
-        return sysconf(_SC_PAGE_SIZE);
-#endif
-    }();
-    return page_size;
-}
-
-/**
- * Alligns `offset` to the operating's system page size such that it subtracts the
- * difference until the nearest page boundary before `offset`, or does nothing if
- * `offset` is already page aligned.
- */
-inline size_t make_offset_page_aligned(size_t offset) noexcept
-{
-    const size_t page_size_ = page_size();
-    // Use integer division to round down to the nearest page alignment.
-    return offset / page_size_ * page_size_;
-}
-
-} // namespace mio
-
-#endif // MIO_PAGE_HEADER

include/mio/shared_mmap.hpp

@@ -1,406 +0,0 @@
-/* Copyright 2017 https://github.com/mandreyel
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy of this
- * software and associated documentation files (the "Software"), to deal in the Software
- * without restriction, including without limitation the rights to use, copy, modify,
- * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be included in all copies
- * or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
- * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
- * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
- * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef MIO_SHARED_MMAP_HEADER
-#define MIO_SHARED_MMAP_HEADER
-
-#include "mio/mmap.hpp"
-
-#include <system_error> // std::error_code
-#include <memory> // std::shared_ptr
-
-namespace mio {
-
-/**
- * Exposes (nearly) the same interface as `basic_mmap`, but endowes it with
- * `std::shared_ptr` semantics.
- *
- * This is not the default behaviour of `basic_mmap` to avoid allocating on the heap if
- * shared semantics are not required.
- */
-template<
-    access_mode AccessMode,
-    typename ByteT
-> class basic_shared_mmap
-{
-    using impl_type = basic_mmap<AccessMode, ByteT>;
-    std::shared_ptr<impl_type> pimpl_;
-
-public:
-    using value_type = typename impl_type::value_type;
-    using size_type = typename impl_type::size_type;
-    using reference = typename impl_type::reference;
-    using const_reference = typename impl_type::const_reference;
-    using pointer = typename impl_type::pointer;
-    using const_pointer = typename impl_type::const_pointer;
-    using difference_type = typename impl_type::difference_type;
-    using iterator = typename impl_type::iterator;
-    using const_iterator = typename impl_type::const_iterator;
-    using reverse_iterator = typename impl_type::reverse_iterator;
-    using const_reverse_iterator = typename impl_type::const_reverse_iterator;
-    using iterator_category = typename impl_type::iterator_category;
-    using handle_type = typename impl_type::handle_type;
-    using mmap_type = impl_type;
-
-    basic_shared_mmap() = default;
-    basic_shared_mmap(const basic_shared_mmap&) = default;
-    basic_shared_mmap& operator=(const basic_shared_mmap&) = default;
-    basic_shared_mmap(basic_shared_mmap&&) = default;
-    basic_shared_mmap& operator=(basic_shared_mmap&&) = default;
-
-    /** Takes ownership of an existing mmap object. */
-    basic_shared_mmap(mmap_type&& mmap)
-        : pimpl_(std::make_shared<mmap_type>(std::move(mmap)))
-    {}
-
-    /** Takes ownership of an existing mmap object. */
-    basic_shared_mmap& operator=(mmap_type&& mmap)
-    {
-        pimpl_ = std::make_shared<mmap_type>(std::move(mmap));
-        return *this;
-    }
-
-    /** Initializes this object with an already established shared mmap. */
-    basic_shared_mmap(std::shared_ptr<mmap_type> mmap) : pimpl_(std::move(mmap)) {}
-
-    /** Initializes this object with an already established shared mmap. */
-    basic_shared_mmap& operator=(std::shared_ptr<mmap_type> mmap)
-    {
-        pimpl_ = std::move(mmap);
-        return *this;
-    }
-
-#ifdef __cpp_exceptions
-    /**
-     * The same as invoking the `map` function, except any error that may occur
-     * while establishing the mapping is wrapped in a `std::system_error` and is
-     * thrown.
-     */
-    template<typename String>
-    basic_shared_mmap(const String& path, const size_type offset = 0, const size_type length = map_entire_file)
-    {
-        std::error_code error;
-        map(path, offset, length, error);
-        if(error) { throw std::system_error(error); }
-    }
-
-    /**
-     * The same as invoking the `map` function, except any error that may occur
-     * while establishing the mapping is wrapped in a `std::system_error` and is
-     * thrown.
-     */
-    basic_shared_mmap(const handle_type handle, const size_type offset = 0, const size_type length = map_entire_file)
-    {
-        std::error_code error;
-        map(handle, offset, length, error);
-        if(error) { throw std::system_error(error); }
-    }
-#endif // __cpp_exceptions
-
-    /**
-     * If this is a read-write mapping and the last reference to the mapping,
-     * the destructor invokes sync. Regardless of the access mode, unmap is
-     * invoked as a final step.
-     */
-    ~basic_shared_mmap() = default;
-
-    /** Returns the underlying `std::shared_ptr` instance that holds the mmap. */
-    std::shared_ptr<mmap_type> get_shared_ptr() { return pimpl_; }
-
-    /**
-     * On UNIX systems 'file_handle' and 'mapping_handle' are the same. On Windows,
-     * however, a mapped region of a file gets its own handle, which is returned by
-     * 'mapping_handle'.
-     */
-    handle_type file_handle() const noexcept
-    {
-        return pimpl_ ? pimpl_->file_handle() : invalid_handle;
-    }
-
-    handle_type mapping_handle() const noexcept
-    {
-        return pimpl_ ? pimpl_->mapping_handle() : invalid_handle;
-    }
-
-    /** Returns whether a valid memory mapping has been created. */
-    bool is_open() const noexcept { return pimpl_ && pimpl_->is_open(); }
-
-    /**
-     * Returns true if no mapping was established, that is, conceptually the
-     * same as though the length that was mapped was 0. This function is
-     * provided so that this class has Container semantics.
-     */
-    bool empty() const noexcept { return !pimpl_ || pimpl_->empty(); }
-
-    /**
-     * `size` and `length` both return the logical length, i.e. the number of bytes
-     * user requested to be mapped, while `mapped_length` returns the actual number of
-     * bytes that were mapped which is a multiple of the underlying operating system's
-     * page allocation granularity.
-     */
-    size_type size() const noexcept { return pimpl_ ? pimpl_->length() : 0; }
-    size_type length() const noexcept { return pimpl_ ? pimpl_->length() : 0; }
-    size_type mapped_length() const noexcept
-    {
-        return pimpl_ ? pimpl_->mapped_length() : 0;
-    }
-
-    /**
-     * Returns a pointer to the first requested byte, or `nullptr` if no memory mapping
-     * exists.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > pointer data() noexcept { return pimpl_->data(); }
-    const_pointer data() const noexcept { return pimpl_ ? pimpl_->data() : nullptr; }
-
-    /**
-     * Returns an iterator to the first requested byte, if a valid memory mapping
-     * exists, otherwise this function call is undefined behaviour.
-     */
-    iterator begin() noexcept { return pimpl_->begin(); }
-    const_iterator begin() const noexcept { return pimpl_->begin(); }
-    const_iterator cbegin() const noexcept { return pimpl_->cbegin(); }
-
-    /**
-     * Returns an iterator one past the last requested byte, if a valid memory mapping
-     * exists, otherwise this function call is undefined behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > iterator end() noexcept { return pimpl_->end(); }
-    const_iterator end() const noexcept { return pimpl_->end(); }
-    const_iterator cend() const noexcept { return pimpl_->cend(); }
-
-    /**
-     * Returns a reverse iterator to the last memory mapped byte, if a valid
-     * memory mapping exists, otherwise this function call is undefined
-     * behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > reverse_iterator rbegin() noexcept { return pimpl_->rbegin(); }
-    const_reverse_iterator rbegin() const noexcept { return pimpl_->rbegin(); }
-    const_reverse_iterator crbegin() const noexcept { return pimpl_->crbegin(); }
-
-    /**
-     * Returns a reverse iterator past the first mapped byte, if a valid memory
-     * mapping exists, otherwise this function call is undefined behaviour.
-     */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > reverse_iterator rend() noexcept { return pimpl_->rend(); }
-    const_reverse_iterator rend() const noexcept { return pimpl_->rend(); }
-    const_reverse_iterator crend() const noexcept { return pimpl_->crend(); }
-
-    /**
-     * Returns a reference to the `i`th byte from the first requested byte (as returned
-     * by `data`). If this is invoked when no valid memory mapping has been created
-     * prior to this call, undefined behaviour ensues.
-     */
-    reference operator[](const size_type i) noexcept { return (*pimpl_)[i]; }
-    const_reference operator[](const size_type i) const noexcept { return (*pimpl_)[i]; }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `path`, which must be a path to an existing file, is used to retrieve a file
-     * handle (which is closed when the object destructs or `unmap` is called), which is
-     * then used to memory map the requested region. Upon failure, `error` is set to
-     * indicate the reason and the object remains in an unmapped state.
-     *
-     * `offset` is the number of bytes, relative to the start of the file, where the
-     * mapping should begin. When specifying it, there is no need to worry about
-     * providing a value that is aligned with the operating system's page allocation
-     * granularity. This is adjusted by the implementation such that the first requested
-     * byte (as returned by `data` or `begin`), so long as `offset` is valid, will be at
-     * `offset` from the start of the file.
-     *
-     * `length` is the number of bytes to map. It may be `map_entire_file`, in which
-     * case a mapping of the entire file is created.
-     */
-    template<typename String>
-    void map(const String& path, const size_type offset,
-        const size_type length, std::error_code& error)
-    {
-        map_impl(path, offset, length, error);
-    }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `path`, which must be a path to an existing file, is used to retrieve a file
-     * handle (which is closed when the object destructs or `unmap` is called), which is
-     * then used to memory map the requested region. Upon failure, `error` is set to
-     * indicate the reason and the object remains in an unmapped state.
-     *
-     * The entire file is mapped.
-     */
-    template<typename String>
-    void map(const String& path, std::error_code& error)
-    {
-        map_impl(path, 0, map_entire_file, error);
-    }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `handle`, which must be a valid file handle, which is used to memory map the
-     * requested region. Upon failure, `error` is set to indicate the reason and the
-     * object remains in an unmapped state.
-     *
-     * `offset` is the number of bytes, relative to the start of the file, where the
-     * mapping should begin. When specifying it, there is no need to worry about
-     * providing a value that is aligned with the operating system's page allocation
-     * granularity. This is adjusted by the implementation such that the first requested
-     * byte (as returned by `data` or `begin`), so long as `offset` is valid, will be at
-     * `offset` from the start of the file.
-     *
-     * `length` is the number of bytes to map. It may be `map_entire_file`, in which
-     * case a mapping of the entire file is created.
-     */
-    void map(const handle_type handle, const size_type offset,
-        const size_type length, std::error_code& error)
-    {
-        map_impl(handle, offset, length, error);
-    }
-
-    /**
-     * Establishes a memory mapping with AccessMode. If the mapping is unsuccesful, the
-     * reason is reported via `error` and the object remains in a state as if this
-     * function hadn't been called.
-     *
-     * `handle`, which must be a valid file handle, which is used to memory map the
-     * requested region. Upon failure, `error` is set to indicate the reason and the
-     * object remains in an unmapped state.
-     *
-     * The entire file is mapped.
-     */
-    void map(const handle_type handle, std::error_code& error)
-    {
-        map_impl(handle, 0, map_entire_file, error);
-    }
-
-    /**
-     * If a valid memory mapping has been created prior to this call, this call
-     * instructs the kernel to unmap the memory region and disassociate this object
-     * from the file.
-     *
-     * The file handle associated with the file that is mapped is only closed if the
-     * mapping was created using a file path. If, on the other hand, an existing
-     * file handle was used to create the mapping, the file handle is not closed.
-     */
-    void unmap() { if(pimpl_) pimpl_->unmap(); }
-
-    void swap(basic_shared_mmap& other) { pimpl_.swap(other.pimpl_); }
-
-    /** Flushes the memory mapped page to disk. Errors are reported via `error`. */
-    template<
-        access_mode A = AccessMode,
-        typename = typename std::enable_if<A == access_mode::write>::type
-    > void sync(std::error_code& error) { if(pimpl_) pimpl_->sync(error); }
-
-    /** All operators compare the underlying `basic_mmap`'s addresses. */
-
-    friend bool operator==(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return a.pimpl_ == b.pimpl_;
-    }
-
-    friend bool operator!=(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return !(a == b);
-    }
-
-    friend bool operator<(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return a.pimpl_ < b.pimpl_;
-    }
-
-    friend bool operator<=(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return a.pimpl_ <= b.pimpl_;
-    }
-
-    friend bool operator>(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return a.pimpl_ > b.pimpl_;
-    }
-
-    friend bool operator>=(const basic_shared_mmap& a, const basic_shared_mmap& b)
-    {
-        return a.pimpl_ >= b.pimpl_;
-    }
-
-private:
-    template<typename MappingToken>
-    void map_impl(const MappingToken& token, const size_type offset,
-        const size_type length, std::error_code& error)
-    {
-        if(!pimpl_)
-        {
-            mmap_type mmap = make_mmap<mmap_type>(token, offset, length, error);
-            if(error) { return; }
-            pimpl_ = std::make_shared<mmap_type>(std::move(mmap));
-        }
-        else
-        {
-            pimpl_->map(token, offset, length, error);
-        }
-    }
-};
-
-/**
- * This is the basis for all read-only mmap objects and should be preferred over
- * directly using basic_shared_mmap.
- */
-template<typename ByteT>
-using basic_shared_mmap_source = basic_shared_mmap<access_mode::read, ByteT>;
-
-/**
- * This is the basis for all read-write mmap objects and should be preferred over
- * directly using basic_shared_mmap.
- */
-template<typename ByteT>
-using basic_shared_mmap_sink = basic_shared_mmap<access_mode::write, ByteT>;
-
-/**
- * These aliases cover the most common use cases, both representing a raw byte stream
- * (either with a char or an unsigned char/uint8_t).
- */
-using shared_mmap_source = basic_shared_mmap_source<char>;
-using shared_ummap_source = basic_shared_mmap_source<unsigned char>;
-
-using shared_mmap_sink = basic_shared_mmap_sink<char>;
-using shared_ummap_sink = basic_shared_mmap_sink<unsigned char>;
-
-} // namespace mio
-
-#endif // MIO_SHARED_MMAP_HEADER

single_include/MemoryMappingByFile.hpp

@@ -0,0 +1,347 @@
+/*
+ * Copyright (C) 2022-2030 Twilight-Dream
+ *
+ * 本文件是 mio 的一部分。
+ *
+ * mio 是自由软件：你可以再分发之和/或依照由自由软件基金会发布的 GNU 通用公共许可证修改之，无论是版本 3 许可证，还是（按你的决定）任何以后版都可以。
+ *
+ * 发布 TDOM-EncryptOrDecryptFile-Reborn 是希望它能有用，但是并无保障;甚至连可销售和符合某个特定的目的都不保证。请参看 GNU 通用公共许可证，了解详情。
+ * 你应该随程序获得一份 GNU 通用公共许可证的复本。如果没有，请看 <https://www.gnu.org/licenses/>。
+ */
+ 
+ /*
+ * Copyright (C) 2022-2030 Twilight-Dream
+ *
+ * This file is part of mio.
+ *
+ * mio is free software: you may redistribute it and/or modify it under the GNU General Public License as published by the Free Software Foundation, either under the Version 3 license, or (at your discretion) any later version.
+ *
+ * mio is released in the hope that it will be useful, but there are no guarantees; not even that it will be marketable and fit a particular purpose. Please see the GNU General Public License for details.
+ * You should get a copy of the GNU General Public License with your program. If not, see <https://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include "mio/mio.hpp"
+
+//将文件数据进行镜像（映射）到操作系统的内存对象。以实现对磁盘的大文件(这里规定大小大于4GB)的字节流模拟访问和修改
+//Mirroring (mapping) file data to the operating system's memory objects. to enable byte stream emulation access and modification of large files (here specified size > 4 giga byte) on disk
+namespace MemoryObjectConfrontationDiskFileData
+{
+	/*
+
+		Use C++ project mio
+
+		Github https://github.com/mandreyel/mio
+
+		An easy to use header-only cross-platform C++11 memory mapping library with an MIT license.
+		mio has been created with the goal to be easily includable (i.e. no dependencies) in any C++ project that needs memory mapped file IO without the need to pull in C++ Boost library.
+		Please feel free to open an issue, I'll try to address any concerns as best I can.
+
+		一个易于使用的头文件跨平台的C++11内存映射库，拥有MIT许可证。
+		创建mio的目的是为了在任何需要内存映射文件IO的C++项目中都能方便地包含（即没有依赖性），而不需要拉入C++ Boost 库。
+		请随时提出问题，我将尽力解决任何问题。
+
+	*/
+
+	template <typename Type>
+	concept TemplateConcept_MemoryMap = std::is_same_v<Type, mio::mmap_source> || std::is_same_v<Type, mio::mmap_sink> || std::is_same_v<Type, mio::ummap_source> || std::is_same_v<Type, mio::ummap_sink>;
+
+	template <typename Type>
+	concept TemplateConcept_MemoryMap_ReadAndWrite = std::is_same_v<Type, mio::mmap_sink> || std::is_same_v<Type, mio::ummap_sink>;
+
+	enum class MemoryMapTypes
+	{
+		SIGNED_READ_AND_WRITE = 0,
+		SIGNED_READ_ONLY = 1,
+		UNSIGNED_READ_AND_WRITE = 2,
+		UNSIGNED_READ_ONLY = 3
+	};
+
+	class MemoryMapPointers
+	{
+
+	private:
+
+		std::unique_ptr<mio::mmap_sink>	   pointer_signed_rw;
+		std::unique_ptr<mio::mmap_source>  pointer_signed_ro;
+		std::unique_ptr<mio::ummap_sink>   pointer_unsigned_rw;
+		std::unique_ptr<mio::ummap_source> pointer_unsigned_ro;
+
+	public:
+
+		std::unique_ptr<mio::mmap_sink>& signed_rw()
+		{
+			return pointer_signed_rw;
+		}
+
+		std::unique_ptr<mio::mmap_source>& signed_ro()
+		{
+			return pointer_signed_ro;
+		}
+
+		std::unique_ptr<mio::ummap_sink>& unsigned_rw()
+		{
+			return pointer_unsigned_rw;
+		}
+
+		std::unique_ptr<mio::ummap_source>& unsigned_ro()
+		{
+			return pointer_unsigned_ro;
+		}
+
+		MemoryMapPointers() noexcept : pointer_signed_rw( nullptr ), pointer_signed_ro( nullptr ), pointer_unsigned_rw( nullptr ), pointer_unsigned_ro( nullptr ) {}
+
+		MemoryMapPointers(MemoryMapPointers& _object) = delete;
+		MemoryMapPointers& operator=(const MemoryMapPointers _object) = delete;
+
+		MemoryMapPointers( MemoryMapTypes map_types )
+		{
+			switch ( map_types )
+			{
+				case MemoryMapTypes::SIGNED_READ_AND_WRITE:
+				{
+					this->pointer_signed_rw = std::unique_ptr<mio::mmap_sink, std::default_delete<mio::mmap_sink>>( new mio::mmap_sink, std::default_delete<mio::mmap_sink>() );
+					break;
+				}
+				case MemoryMapTypes::SIGNED_READ_ONLY:
+				{
+					this->pointer_signed_ro = std::unique_ptr<mio::mmap_source, std::default_delete<mio::mmap_source>>( new mio::mmap_source, std::default_delete<mio::mmap_source>() );
+					break;
+				}
+				case MemoryMapTypes::UNSIGNED_READ_AND_WRITE:
+				{
+					this->pointer_unsigned_rw = std::unique_ptr<mio::ummap_sink, std::default_delete<mio::ummap_sink>>( new mio::ummap_sink, std::default_delete<mio::ummap_sink>() );
+					break;
+				}
+				case MemoryMapTypes::UNSIGNED_READ_ONLY:
+				{
+					this->pointer_unsigned_ro = std::unique_ptr<mio::ummap_source, std::default_delete<mio::ummap_source>>( new mio::ummap_source, std::default_delete<mio::ummap_source>() );
+					break;
+				}
+				default:
+					break;
+			}
+		}
+
+		~MemoryMapPointers()
+		{
+			if ( !( pointer_signed_rw == nullptr ) )
+			{
+				auto* pointer = pointer_signed_rw.release();
+				pointer = nullptr;
+			}
+
+			if ( !( pointer_signed_ro == nullptr ) )
+			{
+				auto* pointer = pointer_signed_ro.release();
+				pointer = nullptr;
+			}
+
+			if ( !( pointer_unsigned_rw == nullptr ) )
+			{
+				auto* pointer = pointer_unsigned_rw.release();
+				pointer = nullptr;
+			}
+
+			if ( !( pointer_unsigned_ro == nullptr ) )
+			{
+				auto* pointer = pointer_unsigned_ro.release();
+				pointer = nullptr;
+			}
+		}
+	};
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	bool MMMO_CheckIsAssocisatedFile( MemoryMapType& mapped_object );
+
+	inline MemoryMapPointers MakeDefaultMemoryMappingObject( MemoryMapTypes map_types );
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	std::tuple<bool, MemoryMapType> MMMO_TryAssociateFile_ToPack( const std::filesystem::path& file_path_name, MemoryMapType* memory_map_pointer );
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	bool MMMO_FromUnpack( std::tuple<bool, MemoryMapType>& associated_data, MemoryMapType& default_memory_map_object);
+
+	template <typename MemoryMapType_ReadAndWrite>
+	requires TemplateConcept_MemoryMap_ReadAndWrite<MemoryMapType_ReadAndWrite>
+	void MMMO_TrySyncDiskFile( MemoryMapType_ReadAndWrite& mapped );
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	bool UnmappingMemoryMapObject( MemoryMapType& mapped );
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	inline bool MMMO_CheckIsAssocisatedFile( MemoryMapType& mapped_object )
+	{
+		if ( !mapped_object.is_mapped() )
+		{
+			std::cerr << CommonToolkit::from_u8string(u8"你开玩笑呢？这个内存映射对象根本就没有关联一个文件。") << std::endl;
+			std::cerr << "Are you kidding me? This memory mapped object is not associated with a file at all." << std::endl;
+			return false;
+		}
+		else
+		{
+			return true;
+		}
+	}
+
+	//创建一个内存映射对象
+	//Create a memory map object
+	inline MemoryMapPointers MakeDefaultMemoryMappingObject( MemoryMapTypes map_types )
+	{
+		return MemoryMapPointers( map_types );
+	}
+
+	//提供一个内存映射对象，然后尝试关联文件
+	//Provide a memory map object and then try to associate the file
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	std::tuple<bool, MemoryMapType> MMMO_TryAssociateFile_ToPack( const std::filesystem::path& file_path_name, MemoryMapType* memory_map_pointer )
+	{
+		auto this_file_path_name = std::move( file_path_name );
+		auto& memory_map_reference = *memory_map_pointer;
+
+		if constexpr( std::same_as<std::remove_reference_t<decltype(memory_map_reference)>, mio::mmap_sink> || std::same_as<std::remove_reference_t<decltype(memory_map_reference)>, mio::ummap_sink> )
+		{
+			std::fstream file_stream_object;
+
+			if ( std::filesystem::exists( file_path_name ) )
+			{
+				std::u8string u8string_extension_name = u8".newfile";
+				this_file_path_name += CommonToolkit::from_u8string(u8string_extension_name);
+				std::filesystem::copy(file_path_name, this_file_path_name);
+
+				//文件打开后立即寻找流的末端
+				//seek to the end of stream immediately after open
+				file_stream_object.open( this_file_path_name, std::ios::in | std::ios::out | std::ios::ate | std::ios::binary );
+
+				if(file_stream_object.is_open())
+				{
+					//立即关闭文件
+					//Close the file now
+					file_stream_object.close();
+				}
+			}
+		}
+
+		memory_map_reference.map( this_file_path_name.string(), 0, mio::map_entire_file );
+
+		if ( !memory_map_reference.is_open() )
+		{
+			std::cerr << CommonToolkit::from_u8string(u8"呃，你确定那个文件的路径确实存在吗？你需要好好检查一下。") << std::endl;
+			std::cerr << "Uh, are you sure the path to that file actually exists? You need to check it properly." << std::endl;
+			
+			std::cerr << CommonToolkit::from_u8string(u8"内存映射对象无效，可能是文件无法访问或者内存不足。\n文件路径是： ")
+						<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+			std::cerr << "The memory mapped object is invalid, probably because the file is inaccessible or out of memory.\nThe file path is. "
+						<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+			UnmappingMemoryMapObject( memory_map_reference );
+			return std::make_tuple( std::move( false ), std::move( memory_map_reference ) );
+		}
+		else
+		{
+			if ( MMMO_CheckIsAssocisatedFile( memory_map_reference ) )
+			{
+				std::cout << CommonToolkit::from_u8string(u8"内存映射对象已经关联文件\n文件路径是： ")
+							<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+				std::cout << "The memory mapped object has associated files.\nThe file path is: "
+							<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+				return std::make_tuple( std::move( true ), std::move( memory_map_reference ) );
+			}
+			else
+			{
+				std::cerr << CommonToolkit::from_u8string(u8"内存映射对象不能关联文件，文件路径是： ")
+							<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+				std::cerr << "The memory mapped objects cannot be associated with files.\nThe file path is. "
+							<< "[" << CommonToolkit::from_u8string(file_path_name.u8string()) << "]" << std::endl;
+				UnmappingMemoryMapObject( memory_map_reference );
+				return std::make_tuple( std::move( false ), std::move( memory_map_reference ) );
+			}
+		}
+	}
+
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	bool MMMO_FromUnpack( std::tuple<bool, MemoryMapType>& associated_data, MemoryMapType& default_memory_map_object )
+	{
+		#if __cplusplus >= 201703L
+
+		auto& [associated_mmap_data_package_status, memory_map_object] = associated_data;
+
+		if ( associated_mmap_data_package_status )
+		{
+			default_memory_map_object = std::move( memory_map_object );
+			return associated_mmap_data_package_status;
+		}
+		else
+		{
+			return associated_mmap_data_package_status;
+		}
+
+		#else
+
+		bool associated_mmap_data_package_status = std::get<bool>( associated_data );
+
+		if ( associated_mmap_data_package_status )
+		{
+			default_memory_map_object = std::move( std::get<MemoryMapType>( associated_data ) );
+			return associated_mmap_data_package_status;
+		}
+		else
+		{
+			return associated_mmap_data_package_status;
+		}
+
+		#endif
+	}
+
+	//已经映射完成的内存对象，只要内存对象管理的数据发生改变时，就需要同步磁盘文件数据进行写入
+	//Whenever the memory object is mapped, the data managed by the memory object is changed, the disk file data needs to be synchronized for writing.
+	template <typename MemoryMapType_ReadAndWrite>
+	requires TemplateConcept_MemoryMap_ReadAndWrite<MemoryMapType_ReadAndWrite>
+	void MMMO_TrySyncDiskFile( MemoryMapType_ReadAndWrite& mapped_object )
+	{
+		if ( mapped_object.is_open() && mapped_object.is_mapped() )
+		{
+			std::cout << CommonToolkit::from_u8string(u8"好了，试着把内存映射对象管理的数据的变化同步到磁盘上。") << std::endl;
+			std::cout << "OK, try synchronizing the changes in the data managed by the memory mapped object to the disk." << std::endl;
+			mapped_object.sync();
+		}
+	}
+
+	//提供一个内存映射对象，然后解除关联文件。
+	//Provide a memory map object and then unassociate the file
+	template <typename MemoryMapType>
+	requires TemplateConcept_MemoryMap<MemoryMapType>
+	inline bool UnmappingMemoryMapObject( MemoryMapType& mapped_object )
+	{
+		if ( MMMO_CheckIsAssocisatedFile( mapped_object ) )
+		{
+			mapped_object.unmap();
+			return true;
+		}
+		else
+		{
+			return false;
+		}
+	}
+
+
+	//测试代码是否可以被编译
+	//Test if the code can be compiled
+	#if 0
+
+	MemoryMapPointers mmp_pointer_object = MakeDefaultMemoryMappingObject(MIO_LibraryHelper::MemoryMapTypes::SIGNED_READ_AND_WRITE);
+	auto* managed_pointer = mmp_pointer_object.signed_rw().get();
+	auto associated_mmap_data_package = MMMO_TryAssociateFile_ToPack(std::string("./filename.dat"), managed_pointer);
+	bool associated_mmap_data_unpackage_status;
+	auto mapped_object = MMMO_FromUnpack(associated_mmap_data_package, associated_mmap_data_unpackage_status);
+	MMMO_TrySyncDiskFile(mapped_object);
+	bool unmake_status = UnmappingMemoryMapObject(mapped_object);
+
+	#endif
+} // namespace MemoryObjectConfrontationDiskFileData

test/CMakeLists.txt

@@ -1,25 +0,0 @@
-configure_file(
-  "${PROJECT_SOURCE_DIR}/cmake/CTestCustom.cmake"
-  "${PROJECT_BINARY_DIR}/CTestCustom.cmake"
-  COPYONLY)
-
-add_executable(mio.test test.cpp)
-target_link_libraries(mio.test PRIVATE mio::mio)
-add_test(NAME mio.test COMMAND mio.test)
-
-if(WIN32)
-    add_executable(mio.unicode.test test.cpp)
-    target_link_libraries(mio.unicode.test PRIVATE mio::mio)
-    target_compile_definitions(mio.unicode.test PRIVATE UNICODE)
-    add_test(NAME mio.unicode.test COMMAND mio.test)
-
-    add_executable(mio.fullwinapi.test test.cpp)
-    target_link_libraries(mio.fullwinapi.test
-      PRIVATE mio::mio_full_winapi)
-    add_test(NAME mio.fullwinapi.test COMMAND mio.fullwinapi.test)
-
-    add_executable(mio.minwinapi.test test.cpp)
-    target_link_libraries(mio.minwinapi.test
-      PRIVATE mio::mio_min_winapi)
-    add_test(NAME mio.minwinapi.test COMMAND mio.minwinapi.test)
-endif()

test/example.cpp

@@ -1,4 +1,3 @@
-#include <mio/mmap.hpp>
 #include <system_error> // for std::error_code
 #include <cstdio> // for std::printf
 #include <cassert>

test/test.cpp

@@ -1,182 +1,253 @@
-#include <mio/mmap.hpp>
-#include <mio/shared_mmap.hpp>
-
 #include <string>
 #include <fstream>
-#include <cstdlib>
 #include <iostream>
 #include <cassert>
-#include <system_error>
 #include <numeric>
+#include <vector>
 
-#ifndef _WIN32
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#endif
+#include "../single_include/mio/mio.hpp"
 
 // Just make sure this compiles.
-#ifdef CXX17
-# include <cstddef>
-using mmap_source = mio::basic_mmap_source<std::byte>;
-#endif
+#include <cstddef>
+using mmap_source_bytes = mio::basic_mmap_source<std::byte>;
 
 template<class MMap>
-void test_at_offset(const MMap& file_view, const std::string& buffer,
-        const size_t offset);
-void test_at_offset(const std::string& buffer, const char* path,
-        const size_t offset, std::error_code& error);
-int handle_error(const std::error_code& error);
+void test_at_offset(const MMap& file_view, const std::string& buffer, const size_t offset);
+inline void test_at_offset(const std::string& buffer, const char* path, const size_t offset);
+
+inline void allocate_file(const std::string& path, const int size)
+{
+	std::ofstream file(path);
+	std::string s(size, '0');
+	file << s;
+}
+
+inline void test_rewrite_file()
+{
+	const auto path = "test_rewrite.txt";
+
+	// NOTE: mio does *not* create the file for you if it doesn't exist! You
+	// must ensure that the file exists before establishing a mapping. It
+	// must also be non-empty. So for illustrative purposes the file is
+	// created now.
+	allocate_file(path, 204800);
+
+	// Read-write memory map the whole file by using `map_entire_file` where the
+	// length of the mapping is otherwise expected, with the factory method.
+	mio::mmap_sink rw_mmap = mio::make_mmap_sink(
+		path, 0, mio::map_entire_file);
+
+	// You can use any iterator based function.
+	std::fill(rw_mmap.begin(), rw_mmap.end(), 'a');
+
+	// Or manually iterate through the mapped region just as if it were any other 
+	// container, and change each byte's value (since this is a read-write mapping).
+	for (auto& b : rw_mmap)
+	{
+		b += 10;
+	}
+
+	// Or just change one value with the subscript operator.
+	const int answer_index = rw_mmap.size() / 2;
+	rw_mmap[answer_index] = 42;
+
+	// Don't forget to flush changes to disk before unmapping. However, if
+	// `rw_mmap` were to go out of scope at this point, the destructor would also
+	// automatically invoke `sync` before `unmap`.
+	rw_mmap.sync();
+
+	// We can then remove the mapping, after which rw_mmap will be in a default
+	// constructed state, i.e. this and the above call to `sync` have the same
+	// effect as if the destructor had been invoked.
+	rw_mmap.unmap();
+
+	// Now create the same mapping, but in read-only mode. Note that calling the
+	// overload without the offset and file length parameters maps the entire
+	// file.
+	mio::mmap_source ro_mmap;
+	ro_mmap.map(path);
+
+	const int the_answer_to_everything = ro_mmap[answer_index];
+	assert(the_answer_to_everything == 42);
+}
+
+inline void test_error_case(char* path, const std::string& buffer)
+{
+
+#define CHECK_INVALID_MMAP(m) do { \
+        assert(m.empty()); \
+        assert(!m.is_open()); \
+        } while(0)
+
+	mio::mmap_source m;
+
+	// See if mapping an invalid file results in an error.
+	m = mio::make_mmap_source("garbage-that-hopefully-doesnt-exist", 0, 0);
+	CHECK_INVALID_MMAP(m);
+
+	// Empty path?
+	m = mio::make_mmap_source(static_cast<const char*>(0), 0, 0);
+	CHECK_INVALID_MMAP(m);
+	m = mio::make_mmap_source(std::string(), 0, 0);
+	CHECK_INVALID_MMAP(m);
+
+	// Invalid handle?
+	m = mio::make_mmap_source(mio::invalid_handle, 0, 0);
+	CHECK_INVALID_MMAP(m);
+
+	// Invalid offset?
+	m = mio::make_mmap_source(path, 100 * buffer.size(), buffer.size());
+	CHECK_INVALID_MMAP(m);
+}
 
 int main()
 {
-    std::error_code error;
+	std::system("chcp 65001");
 
-    // Make sure mio compiles with non-const char* strings too.
-    const char _path[] = "test-file";
-    const int path_len = sizeof(_path);
-    char* path = new char[path_len];
-    std::copy(_path, _path + path_len, path);
+	// Make sure mio compiles with non-const char* strings too.
+	const char _path[] = "test-file";
+	const int path_len = sizeof(_path);
+	char* path = new char[path_len];
+	std::copy(_path, _path + path_len, path);
 
-    const auto page_size = mio::page_size();
-    // Fill buffer, then write it to file.
-    const int file_size = 4 * page_size - 250; // 16134, if page size is 4KiB
-    std::string buffer(file_size, 0);
-    // Start at first printable ASCII character.
-    char v = 33;
-    for (auto& b : buffer) {
-       b = v;
-       ++v; 
-       // Limit to last printable ASCII character.
-       v %= 126;
-       if(v == 0) {
-           v = 33;
-       }
-    }
+	const auto page_size = mio::page_size();
+	// Fill buffer, then write it to file.
+	const int file_size = 4 * page_size - 250; // 16134, if page size is 4KiB
+	std::string buffer(file_size, 0);
+	// Start at first printable ASCII character.
+	char v = 33;
+	for (auto& b : buffer) {
+		b = v;
+		++v;
+		// Limit to last printable ASCII character.
+		v %= 126;
+		if (v == 0) {
+			v = 33;
+		}
+	}
 
-    std::ofstream file(path);
-    file << buffer;
-    file.close();
+	std::ofstream file(path);
+	file << buffer;
+	file.close();
 
-    // Test whole file mapping.
-    test_at_offset(buffer, path, 0, error);
-    if (error) { return handle_error(error); }
+	// Test whole file mapping.
+	test_at_offset(buffer, path, 0);
 
-    // Test starting from below the page size.
-    test_at_offset(buffer, path, page_size - 3, error);
-    if (error) { return handle_error(error); }
+	//Test starting from below the page size.
+	test_at_offset(buffer, path, page_size - 3);
 
-    // Test starting from above the page size.
-    test_at_offset(buffer, path, page_size + 3, error);
-    if (error) { return handle_error(error); }
+	// Test starting from above the page size.
+	test_at_offset(buffer, path, page_size + 3);
 
-    // Test starting from above the page size.
-    test_at_offset(buffer, path, 2 * page_size + 3, error);
-    if (error) { return handle_error(error); }
+	// Test starting from above the page size.
+	test_at_offset(buffer, path, 2 * page_size + 3);
 
-    {
-#define CHECK_INVALID_MMAP(m) do { \
-        assert(error); \
-        assert(m.empty()); \
-        assert(!m.is_open()); \
-        error.clear(); } while(0)
+	std::cout << "Continuing with tests..." << std::endl;
 
-        mio::mmap_source m;
+	//Uncomment this line code for checking test error cases.
+	//test_error_case(path, buffer);
 
-        // See if mapping an invalid file results in an error.
-        m = mio::make_mmap_source("garbage-that-hopefully-doesnt-exist", 0, 0, error);
-        CHECK_INVALID_MMAP(m);
-
-        // Empty path?
-        m = mio::make_mmap_source(static_cast<const char*>(0), 0, 0, error);
-        CHECK_INVALID_MMAP(m);
-        m = mio::make_mmap_source(std::string(), 0, 0, error);
-        CHECK_INVALID_MMAP(m);
-
-        // Invalid handle?
-        m = mio::make_mmap_source(mio::invalid_handle, 0, 0, error);
-        CHECK_INVALID_MMAP(m);
-
-        // Invalid offset?
-        m = mio::make_mmap_source(path, 100 * buffer.size(), buffer.size(), error);
-        CHECK_INVALID_MMAP(m);
-    }
-
-    // Make sure these compile.
-    {
-        mio::ummap_source _1;
-        mio::shared_ummap_source _2;
-        // Make sure shared_mmap mapping compiles as all testing was done on
-        // normal mmaps.
-        mio::shared_mmap_source _3(path, 0, mio::map_entire_file);
-        auto _4 = mio::make_mmap_source(path, error);
-        auto _5 = mio::make_mmap<mio::shared_mmap_source>(path, 0, mio::map_entire_file, error);
+	// Make sure these compile.
+	{
+		mio::ummap_source _1;
+		mio::shared_ummap_source _2;
+		// Make sure shared_mmap mapping compiles as all testing was done on
+		// normal mmaps.
+		mio::shared_mmap_source _3(path, 0, mio::map_entire_file);
+		auto _4 = mio::make_mmap_source(path);
+		auto _5 = mio::make_mmap<mio::shared_mmap_source>(path, 0, mio::map_entire_file);
 #ifdef _WIN32
-        const wchar_t* wpath1 = L"dasfsf";
-        auto _6 = mio::make_mmap_source(wpath1, error);
-        mio::mmap_source _7;
-        _7.map(wpath1, error);
-        const std::wstring wpath2 = wpath1;
-        auto _8 = mio::make_mmap_source(wpath2, error);
-        mio::mmap_source _9;
-        _9.map(wpath1, error);
-#else
-        const int fd = open(path, O_RDONLY);
-        mio::mmap_source _fdmmap(fd, 0, mio::map_entire_file);
-        _fdmmap.unmap();
-        _fdmmap.map(fd, error);
-#endif
-    }
+		const std::wstring wpath1 = L"file";
 
-    std::printf("all tests passed!\n");
+		// If the file can be opened, perform make_mmap_source and mapping.
+		if (std::filesystem::exists(wpath1))
+		{
+			auto _6 = mio::make_mmap_source(wpath1);
+			mio::mmap_source _7;
+			_7.map(wpath1);
+		}
+		else
+		{
+			std::wcerr << L"Cannot open file: " << wpath1 << std::endl;
+		}
+
+		// Other operations that must execute regardless.
+		// Even if the file is not openable, these lines are executed.
+		const std::wstring wpath2 = wpath1 + L"000";
+		if (std::filesystem::exists(wpath2))
+		{
+			auto _8 = mio::make_mmap_source(wpath2);
+			mio::mmap_source _9;
+			_9.map(wpath1);
+		}
+		else
+		{
+			std::wcerr << L"Cannot open file: " << wpath2 << std::endl;
+		}
+#else
+		const char* path = "path_to_file";  // Replace with your actual file path
+		const int fd = open(path, O_RDONLY);
+
+		if (fd < 0)
+		{
+			std::cerr << "Failed to open file: " << path << std::endl;
+		}
+		else
+		{
+			// File opened successfully, proceed with mmap operations
+			mio::mmap_source _fdmmap(fd, 0, mio::map_entire_file);
+			// Unmap first if needed
+			_fdmmap.unmap();
+			// Remap using the same file descriptor
+			_fdmmap.map(fd);
+
+			// Close the file descriptor if it's no longer needed
+			close(fd);
+		}
+#endif
+	}
+
+	std::printf("all tests passed!\n");
 }
 
 void test_at_offset(const std::string& buffer, const char* path,
-        const size_t offset, std::error_code& error)
+	const size_t offset)
 {
-    // Sanity check.
-    assert(offset < buffer.size());
+	// Sanity check.
+	assert(offset < buffer.size());
 
-    // Map the region of the file to which buffer was written.
-    mio::mmap_source file_view = mio::make_mmap_source(
-            path, offset, mio::map_entire_file, error);
-    if(error) { return; }
+	// Map the region of the file to which buffer was written.
+	mio::mmap_source file_view = mio::make_mmap_source(path, offset, mio::map_entire_file);
 
-    assert(file_view.is_open());
-    const size_t mapped_size = buffer.size() - offset;
-    assert(file_view.size() == mapped_size);
+	assert(file_view.is_open());
+	const size_t mapped_size = buffer.size() - offset;
+	assert(file_view.size() == mapped_size);
 
-    test_at_offset(file_view, buffer, offset);
+	test_at_offset(file_view, buffer, offset);
 
-    // Turn file_view into a shared mmap.
-    mio::shared_mmap_source shared_file_view(std::move(file_view));
-    assert(!file_view.is_open());
-    assert(shared_file_view.is_open());
-    assert(shared_file_view.size() == mapped_size);
+	// Turn file_view into a shared mmap.
+	mio::shared_mmap_source shared_file_view(std::move(file_view));
+	assert(!file_view.is_open());
+	assert(shared_file_view.is_open());
+	assert(shared_file_view.size() == mapped_size);
 
-    //test_at_offset(shared_file_view, buffer, offset);
+	//test_at_offset(shared_file_view, buffer, offset);
 }
 
 template<class MMap>
-void test_at_offset(const MMap& file_view, const std::string& buffer,
-        const size_t offset)
+void test_at_offset(const MMap& file_view, const std::string& buffer, const size_t offset)
 {
-    // Then verify that mmap's bytes correspond to that of buffer.
-    for(size_t buf_idx = offset, view_idx = 0;
-            buf_idx < buffer.size() && view_idx < file_view.size();
-            ++buf_idx, ++view_idx) {
-        if(file_view[view_idx] != buffer[buf_idx]) {
-            std::printf("%luth byte mismatch: expected(%d) <> actual(%d)",
-                    buf_idx, buffer[buf_idx], file_view[view_idx]);
-            std::cout << std::flush;
-            assert(0);
-        }
-    }
-}
-
-int handle_error(const std::error_code& error)
-{
-    const auto& errmsg = error.message();
-    std::printf("Error mapping file: %s, exiting...\n", errmsg.c_str());
-    return error.value();
+	// Then verify that mmap's bytes correspond to that of buffer.
+	for (size_t buf_idx = offset, view_idx = 0;
+		buf_idx < buffer.size() && view_idx < file_view.size();
+		++buf_idx, ++view_idx)
+	{
+		if (file_view[view_idx] != buffer[buf_idx])
+		{
+			std::printf("%luth byte mismatch: expected(%d) <> actual(%d)",
+				buf_idx, buffer[buf_idx], file_view[view_idx]);
+			std::cout << std::flush;
+			assert(0);
+		}
+	}
 }

third_party/LICENSE.md

@@ -1,28 +0,0 @@
-amalgamate.py - Amalgamate C source and header files
-Copyright (c) 2012, Erik Edlund <erik.edlund@32767.se>
-
-Redistribution and use in source and binary forms, with or without modification,
-are permitted provided that the following conditions are met:
-
- * Redistributions of source code must retain the above copyright notice,
-   this list of conditions and the following disclaimer.
-
- * Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
- * Neither the name of Erik Edlund, nor the names of its contributors may
-   be used to endorse or promote products derived from this software without
-   specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-

third_party/amalgamate.py

@@ -1,300 +0,0 @@
-#!/usr/bin/env python
-# coding=utf-8
-
-# amalgamate.py - Amalgamate C source and header files.
-# Copyright (c) 2012, Erik Edlund <erik.edlund@32767.se>
-# 
-# Redistribution and use in source and binary forms, with or without modification,
-# are permitted provided that the following conditions are met:
-# 
-#  * Redistributions of source code must retain the above copyright notice,
-#  this list of conditions and the following disclaimer.
-# 
-#  * Redistributions in binary form must reproduce the above copyright notice,
-#  this list of conditions and the following disclaimer in the documentation
-#  and/or other materials provided with the distribution.
-# 
-#  * Neither the name of Erik Edlund, nor the names of its contributors may
-#  be used to endorse or promote products derived from this software without
-#  specific prior written permission.
-# 
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
-# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-from __future__ import division
-from __future__ import print_function
-from __future__ import unicode_literals
-
-import argparse
-import datetime
-import json
-import os
-import re
-
-
-class Amalgamation(object):
-
-    # Prepends self.source_path to file_path if needed.
-    def actual_path(self, file_path):
-        if not os.path.isabs(file_path):
-            file_path = os.path.join(self.source_path, file_path)
-        return file_path
-
-    # Search included file_path in self.include_paths and
-    # in source_dir if specified.
-    def find_included_file(self, file_path, source_dir):
-        search_dirs = self.include_paths[:]
-        if source_dir:
-            search_dirs.insert(0, source_dir)
-
-        for search_dir in search_dirs:
-            search_path = os.path.join(search_dir, file_path)
-            if os.path.isfile(self.actual_path(search_path)):
-                return search_path
-        return None
-
-    def __init__(self, args):
-        with open(args.config, 'r') as f:
-            config = json.loads(f.read())
-            for key in config:
-                setattr(self, key, config[key])
-
-            self.verbose = args.verbose == "yes"
-            self.prologue = args.prologue
-            self.source_path = args.source_path
-            self.included_files = []
-
-    # Generate the amalgamation and write it to the target file.
-    def generate(self):
-        amalgamation = ""
-
-        if self.prologue:
-            with open(self.prologue, 'r') as f:
-                amalgamation += datetime.datetime.now().strftime(f.read())
-
-        if self.verbose:
-            print("Config:")
-            print(" target        = {0}".format(self.target))
-            print(" working_dir   = {0}".format(os.getcwd()))
-            print(" include_paths = {0}".format(self.include_paths))
-        print("Creating amalgamation:")
-        for file_path in self.sources:
-            # Do not check the include paths while processing the source
-            # list, all given source paths must be correct.
-            # actual_path = self.actual_path(file_path)
-            print(" - processing \"{0}\"".format(file_path))
-            t = TranslationUnit(file_path, self, True)
-            amalgamation += t.content
-
-        with open(self.target, 'w') as f:
-            f.write(amalgamation)
-
-        print("...done!\n")
-        if self.verbose:
-            print("Files processed: {0}".format(self.sources))
-            print("Files included: {0}".format(self.included_files))
-        print("")
-
-
-def _is_within(match, matches):
-    for m in matches:
-        if match.start() > m.start() and \
-                match.end() < m.end():
-            return True
-    return False
-
-
-class TranslationUnit(object):
-    # // C++ comment.
-    cpp_comment_pattern = re.compile(r"//.*?\n")
-
-    # /* C comment. */
-    c_comment_pattern = re.compile(r"/\*.*?\*/", re.S)
-
-    # "complex \"stri\\\ng\" value".
-    string_pattern = re.compile("[^']" r'".*?(?<=[^\\])"', re.S)
-
-    # Handle simple include directives. Support for advanced
-    # directives where macros and defines needs to expanded is
-    # not a concern right now.
-    include_pattern = re.compile(
-        r'#\s*include\s+(<|")(?P<path>.*?)("|>)', re.S)
-
-    # #pragma once
-    pragma_once_pattern = re.compile(r'#\s*pragma\s+once', re.S)
-
-    # Search for pattern in self.content, add the match to
-    # contexts if found and update the index accordingly.
-    def _search_content(self, index, pattern, contexts):
-        match = pattern.search(self.content, index)
-        if match:
-            contexts.append(match)
-            return match.end()
-        return index + 2
-
-    # Return all the skippable contexts, i.e., comments and strings
-    def _find_skippable_contexts(self):
-        # Find contexts in the content in which a found include
-        # directive should not be processed.
-        skippable_contexts = []
-
-        # Walk through the content char by char, and try to grab
-        # skippable contexts using regular expressions when found.
-        i = 1
-        content_len = len(self.content)
-        while i < content_len:
-            j = i - 1
-            current = self.content[i]
-            previous = self.content[j]
-
-            if current == '"':
-                # String value.
-                i = self._search_content(j, self.string_pattern,
-                                         skippable_contexts)
-            elif current == '*' and previous == '/':
-                # C style comment.
-                i = self._search_content(j, self.c_comment_pattern,
-                                         skippable_contexts)
-            elif current == '/' and previous == '/':
-                # C++ style comment.
-                i = self._search_content(j, self.cpp_comment_pattern,
-                                         skippable_contexts)
-            else:
-                # Skip to the next char.
-                i += 1
-
-        return skippable_contexts
-
-    # Returns True if the match is within list of other matches
-
-    # Removes pragma once from content
-    def _process_pragma_once(self):
-        content_len = len(self.content)
-        if content_len < len("#include <x>"):
-            return 0
-
-        # Find contexts in the content in which a found include
-        # directive should not be processed.
-        skippable_contexts = self._find_skippable_contexts()
-
-        pragmas = []
-        pragma_once_match = self.pragma_once_pattern.search(self.content)
-        while pragma_once_match:
-            if not _is_within(pragma_once_match, skippable_contexts):
-                pragmas.append(pragma_once_match)
-
-            pragma_once_match = self.pragma_once_pattern.search(self.content,
-                                                                pragma_once_match.end())
-
-        # Handle all collected pragma once directives.
-        prev_end = 0
-        tmp_content = ''
-        for pragma_match in pragmas:
-            tmp_content += self.content[prev_end:pragma_match.start()]
-            prev_end = pragma_match.end()
-        tmp_content += self.content[prev_end:]
-        self.content = tmp_content
-
-    # Include all trivial #include directives into self.content.
-    def _process_includes(self):
-        content_len = len(self.content)
-        if content_len < len("#include <x>"):
-            return 0
-
-        # Find contexts in the content in which a found include
-        # directive should not be processed.
-        skippable_contexts = self._find_skippable_contexts()
-
-        # Search for include directives in the content, collect those
-        # which should be included into the content.
-        includes = []
-        include_match = self.include_pattern.search(self.content)
-        while include_match:
-            if not _is_within(include_match, skippable_contexts):
-                include_path = include_match.group("path")
-                search_same_dir = include_match.group(1) == '"'
-                found_included_path = self.amalgamation.find_included_file(
-                    include_path, self.file_dir if search_same_dir else None)
-                if found_included_path:
-                    includes.append((include_match, found_included_path))
-
-            include_match = self.include_pattern.search(self.content,
-                                                        include_match.end())
-
-        # Handle all collected include directives.
-        prev_end = 0
-        tmp_content = ''
-        for include in includes:
-            include_match, found_included_path = include
-            tmp_content += self.content[prev_end:include_match.start()]
-            tmp_content += "// {0}\n".format(include_match.group(0))
-            if found_included_path not in self.amalgamation.included_files:
-                t = TranslationUnit(found_included_path, self.amalgamation, False)
-                tmp_content += t.content
-            prev_end = include_match.end()
-        tmp_content += self.content[prev_end:]
-        self.content = tmp_content
-
-        return len(includes)
-
-    # Make all content processing
-    def _process(self):
-        if not self.is_root:
-            self._process_pragma_once()
-        self._process_includes()
-
-    def __init__(self, file_path, amalgamation, is_root):
-        self.file_path = file_path
-        self.file_dir = os.path.dirname(file_path)
-        self.amalgamation = amalgamation
-        self.is_root = is_root
-
-        self.amalgamation.included_files.append(self.file_path)
-
-        actual_path = self.amalgamation.actual_path(file_path)
-        if not os.path.isfile(actual_path):
-            raise IOError("File not found: \"{0}\"".format(file_path))
-        with open(actual_path, 'r') as f:
-            self.content = f.read()
-            self._process()
-
-
-def main():
-    description = "Amalgamate C source and header files."
-    usage = " ".join([
-        "amalgamate.py",
-        "[-v]",
-        "-c path/to/config.json",
-        "-s path/to/source/dir",
-        "[-p path/to/prologue.(c|h)]"
-    ])
-    argsparser = argparse.ArgumentParser(
-        description=description, usage=usage)
-
-    argsparser.add_argument("-v", "--verbose", dest="verbose",
-                            choices=["yes", "no"], metavar="", help="be verbose")
-
-    argsparser.add_argument("-c", "--config", dest="config",
-                            required=True, metavar="", help="path to a JSON config file")
-
-    argsparser.add_argument("-s", "--source", dest="source_path",
-                            required=True, metavar="", help="source code path")
-
-    argsparser.add_argument("-p", "--prologue", dest="prologue",
-                            required=False, metavar="", help="path to a C prologue file")
-
-    amalgamation = Amalgamation(argsparser.parse_args())
-    amalgamation.generate()
-
-
-if __name__ == "__main__":
-    main()
-

third_party/config.json

@@ -1,11 +0,0 @@
-{
-	"project": "Cross-platform C++11 header-only library for memory mapped file IO",
-	"target": "../single_include/mio/mio.hpp",
-	"sources": [
-		"../include/mio/mmap.hpp",
-		"../include/mio/page.hpp",
-		"../include/mio/shared_mmap.hpp"
-	],
-	"include_paths": ["../include"]
-}
-