Merge pull request #338 from Gravecat/mingw-fix

Fixes compilation on GCC/MinGW

.github/workflows/alpine.yml

@@ -18,7 +18,7 @@ jobs:
           - riscv64
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
 
       - name: Install latest Alpine Linux for ${{ matrix.arch }}
         uses: jirutka/setup-alpine@v1

.github/workflows/amalgamate-ubuntu24.yml

@@ -1,12 +1,12 @@
-name: Amalgamate Ubuntu 20.04 CI (GCC 9)
+name: Amalgamate Ubuntu 24.04 CI
 
 on: [push, pull_request]
 
 jobs:
   ubuntu-build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Compile with amalgamation
         run: |
           mkdir build &&

.github/workflows/cifuzz.yml

@@ -20,14 +20,14 @@ jobs:
        fuzz-seconds: 300
        output-sarif: true
    - name: Upload Crash
-     uses: actions/upload-artifact@v4
+     uses: actions/upload-artifact@v5
      if: failure() && steps.build.outcome == 'success'
      with:
        name: artifacts
        path: ./out/artifacts
    - name: Upload Sarif
      if: always() && steps.build.outcome == 'success'
-     uses: github/codeql-action/upload-sarif@v3
+     uses: github/codeql-action/upload-sarif@v4
      with:
       # Path to SARIF file relative to the root of the repository
       sarif_file: cifuzz-sarif/results.sarif

.github/workflows/emscripten.yml

@@ -0,0 +1,17 @@
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.2.2
+      - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6.0.0
+      - uses: mymindstorm/setup-emsdk@6ab9eb1bda2574c4ddb79809fc9247783eaf9021 # v14
+      - name: Verify
+        run: emcc -v
+      - name: Checkout
+        uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v3.6.0
+      - name: Configure
+        run: emcmake cmake -B build
+      - name: Build # We build but do not test
+        run: cmake --build build

.github/workflows/lint_and_format_check.yml

@@ -24,10 +24,10 @@ jobs:
   lint-and-format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@9a9194f87191a7e9055e3e9b95b8cfb13023bb08 # v4.1.7
+      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493 # v4.1.7
 
       - name: Run clang-format
-        uses: jidicula/clang-format-action@d05cecd4a1a5b7e64c22f5a468456135a43f13f6 # v4.14.0
+        uses: jidicula/clang-format-action@4726374d1aa3c6aecf132e5197e498979588ebc8 # v4.15.0
         with:
           clang-format-version: '17'
 

.github/workflows/msys2-clang.yml

@@ -23,7 +23,7 @@ jobs:
       CMAKE_GENERATOR: Ninja
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: msys2/setup-msys2@v2
         with:
           update: true

.github/workflows/msys2.yml

@@ -29,7 +29,7 @@ jobs:
       CMAKE_GENERATOR: Ninja
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: msys2/setup-msys2@v2
         with:
           update: true

.github/workflows/on-release.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       
       - name: Amalgamate fast_float.h
         run: |

.github/workflows/risc.yml

@@ -0,0 +1,23 @@
+name: Ubuntu RISC-V rvv VLEN=128 (clang 17)
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04
+    steps:
+    - uses: actions/checkout@v5
+    - name: Install packages
+      run: |
+        sudo apt-get update -q -y
+        sudo apt-get install -y cmake make g++-riscv64-linux-gnu qemu-user-static clang-17
+    - name: Build
+      run: |
+        CXX=clang++-17 CXXFLAGS="--target=riscv64-linux-gnu -march=rv64gcv" \
+        cmake --toolchain=cmake/toolchains-ci/riscv64-linux-gnu.cmake -DCMAKE_BUILD_TYPE=Release -B build
+        cmake --build build/ -j$(nproc)
+    - name: Test VLEN=128
+      run: |
+        export QEMU_LD_PREFIX="/usr/riscv64-linux-gnu"
+        export QEMU_CPU="rv64,v=on,vlen=128,rvv_ta_all_1s=on,rvv_ma_all_1s=on"
+        ctest --timeout 1800 --output-on-failure --test-dir build -j $(nproc)

.github/workflows/s390x.yml

@@ -12,7 +12,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: uraimo/run-on-arch-action@v3
         name: Test
         id: runcmd

.github/workflows/ubuntu20-fastmath.yml

@@ -1,16 +0,0 @@
-name: Ubuntu 20.04 CI (GCC 9, fast-math)
-
-on: [push, pull_request]
-
-jobs:
-  ubuntu-build:
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: actions/checkout@v4
-      - name: Use cmake
-        run: |
-          mkdir build &&
-          cd build &&
-          cmake -DCMAKE_CXX_FLAGS="-ffast-math" -DFASTFLOAT_TEST=ON ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure

.github/workflows/ubuntu20.yml

@@ -1,21 +0,0 @@
-name: Ubuntu 20.04 CI (GCC 9)
-
-on: [push, pull_request]
-
-jobs:
-  ubuntu-build:
-    runs-on: ubuntu-20.04
-    steps:
-      - uses: actions/checkout@v4
-      - name: Use cmake
-        run: |
-          mkdir build &&
-          cd build &&
-          cmake  ${{matrix.cxx}} ${{matrix.arch}} -DFASTFLOAT_TEST=ON -DCMAKE_INSTALL_PREFIX:PATH=destination ..  &&
-          cmake --build .   &&
-          ctest --output-on-failure  &&
-          cmake --install . &&
-          cd ../tests/installation_tests/find &&
-          mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../build/destination .. &&  cmake --build . &&
-          cd ../../issue72_installation  &&
-          mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX:PATH=../../../build/destination .. &&  cmake --build .

.github/workflows/ubuntu22-clang.yml

@@ -6,7 +6,7 @@ jobs:
   ubuntu-build:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Install clang++-14
         run: sudo apt-get install -y clang++-14
       - name: Use cmake

.github/workflows/ubuntu22-gcc12.yml

@@ -6,7 +6,7 @@ jobs:
   ubuntu-build:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use cmake
         run: |
           mkdir build &&

.github/workflows/ubuntu22-sanitize.yml

@@ -6,7 +6,7 @@ jobs:
   ubuntu-build:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use cmake
         run: |
           mkdir build &&

.github/workflows/ubuntu22.yml

@@ -6,7 +6,7 @@ jobs:
   ubuntu-build:
     runs-on: ubuntu-22.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use cmake
         run: |
           mkdir build &&

.github/workflows/ubuntu24-cxx20.yml

@@ -1,14 +1,14 @@
-name: Ubuntu 20.04 CI (C++20)
+name: Ubuntu 24.04 CI
 
 on: [push, pull_request]
 
 jobs:
   ubuntu-build:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     strategy:
       fail-fast: false
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use cmake
         run: |
           mkdir build &&

.github/workflows/ubuntu24.yml

@@ -6,7 +6,7 @@ jobs:
   ubuntu-build:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: Use cmake
         run: |
           set -xe

.github/workflows/vs17-arm-ci.yml

@@ -14,7 +14,7 @@ jobs:
           - {gen: Visual Studio 17 2022, arch: ARM64, cfg: Debug}
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: configure
         run: |
           cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}} -DCMAKE_CROSSCOMPILING=1 -DFASTFLOAT_TEST=ON

.github/workflows/vs17-ci.yml

@@ -16,10 +16,10 @@ jobs:
           - {gen: Visual Studio 17 2022, arch: x64, cfg: Debug}
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: configure
         run: |
-          cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}} -DFASTFLOAT_TEST=ON -DCMAKE_INSTALL_PREFIX:PATH=destination
+          cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}} -DFASTFLOAT_BENCHMARKS=ON  -DFASTFLOAT_TEST=ON -DCMAKE_INSTALL_PREFIX:PATH=destination
       - name: build
         run: |
           cmake --build build --verbose --config ${{matrix.cfg}} --parallel

.github/workflows/vs17-clang-ci.yml

@@ -16,10 +16,10 @@ jobs:
           - {gen: Visual Studio 17 2022, arch: x64, cfg: Debug}
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: Configure
         run: |
-          cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}} -T ClangCL -DFASTFLOAT_TEST=ON
+          cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}} -DFASTFLOAT_BENCHMARKS=ON -T ClangCL -DFASTFLOAT_TEST=ON
       - name: Build
         run: cmake --build build --config ${{matrix.cfg}} --parallel --verbose
       - name: Run basic tests

.github/workflows/vs17-cxx20.yml

@@ -16,7 +16,7 @@ jobs:
           - {gen: Visual Studio 17 2022, arch: x64, cfg: Debug}
     steps:
       - name: checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
       - name: configure
         run: >-
           cmake -S . -B build -G "${{matrix.gen}}" -A ${{matrix.arch}}

CMakeLists.txt

@@ -1,6 +1,7 @@
-cmake_minimum_required(VERSION 3.9)
+cmake_minimum_required(VERSION 3.14)
 
-project(fast_float VERSION 8.0.1 LANGUAGES CXX)
+
+project(fast_float VERSION 8.1.0 LANGUAGES CXX)
 set(FASTFLOAT_CXX_STANDARD 11 CACHE STRING "the C++ standard to use for fastfloat")
 set(CMAKE_CXX_STANDARD ${FASTFLOAT_CXX_STANDARD})
 option(FASTFLOAT_TEST "Enable tests" OFF)

README.md

@@ -57,6 +57,7 @@ Example:
 ```C++
 #include "fast_float/fast_float.h"
 #include <iostream>
+#include <string>
 
 int main() {
   std::string input = "3.1416 xyz ";
@@ -68,6 +69,25 @@ int main() {
 }
 ```
 
+Though the C++17 standard has you do a comparison with `std::errc()` to check whether the conversion worked, you can avoid it by casting the result to a `bool` like so:
+
+```cpp
+#include "fast_float/fast_float.h"
+#include <iostream>
+#include <string>
+
+int main() {
+  std::string input = "3.1416 xyz ";
+  double result;
+  if(auto answer = fast_float::from_chars(input.data(), input.data() + input.size(), result)) {
+    std::cout << "parsed the number " << result << std::endl;
+    return EXIT_SUCCESS;
+  }
+  std::cerr << "failed to parse " << result << std::endl;
+  return EXIT_FAILURE;
+}
+```
+
 You can parse delimited numbers:
 
 ```C++
@@ -357,6 +377,51 @@ int main() {
 }
 ```
 
+## Multiplication of an integer by a power of 10
+An integer `W` can be multiplied by a power of ten `10^Q` and
+converted to `double` with correctly rounded value
+(in "round to nearest, tie to even" fashion) using
+`fast_float::integer_times_pow10()`, e.g.:
+```C++
+const uint64_t W = 12345678901234567;
+const int Q = 23;
+const double result = fast_float::integer_times_pow10(W, Q);
+std::cout.precision(17);
+std::cout << W << " * 10^" << Q << " = " << result << " ("
+  << (result == 12345678901234567e23 ? "==" : "!=") << "expected)\n";
+```
+outputs
+```
+12345678901234567 * 10^23 = 1.2345678901234567e+39 (==expected)
+```
+`fast_float::integer_times_pow10()` gives the same result as
+using `fast_float::from_chars()` when parsing the string `"WeQ"`
+(in this example `"12345678901234567e23"`),
+except `fast_float::integer_times_pow10()` does not report out-of-range errors, and
+underflows to zero or overflows to infinity when the resulting value is
+out of range.
+
+You can use template overloads to get the result converted to different
+supported floating-point types: `float`, `double`, etc.
+For example, to get result as `float` use
+`fast_float::integer_times_pow10<float>()` specialization:
+```C++
+const uint64_t W = 12345678;
+const int Q = 23;
+const float result = fast_float::integer_times_pow10<float>(W, Q);
+std::cout.precision(9);
+std::cout << "float: " << W << " * 10^" << Q << " = " << result << " ("
+          << (result == 12345678e23f ? "==" : "!=") << "expected)\n";
+```
+outputs
+```
+float: 12345678 * 10^23 = 1.23456782e+30 (==expected)
+```
+
+Overloads of `fast_float::integer_times_pow10()` are provided for
+signed and unsigned integer types: `int64_t`, `uint64_t`, etc.
+
+
 ## Users and Related Work
 
 The fast_float library is part of:
@@ -364,6 +429,8 @@ The fast_float library is part of:
 * GCC (as of version 12): the `from_chars` function in GCC relies on fast_float,
 * [Chromium](https://github.com/Chromium/Chromium), the engine behind Google
   Chrome, Microsoft Edge, and Opera,
+* Boost JSON, MySQL, etc.
+* Blender
 * [WebKit](https://github.com/WebKit/WebKit), the engine behind Safari (Apple's
   web browser),
 * [DuckDB](https://duckdb.org),
@@ -376,7 +443,10 @@ The fast_float library is part of:
 The fastfloat algorithm is part of the [LLVM standard
 libraries](https://github.com/llvm/llvm-project/commit/87c016078ad72c46505461e4ff8bfa04819fe7ba).
 There is a [derived implementation part of
-AdaCore](https://github.com/AdaCore/VSS).
+AdaCore](https://github.com/AdaCore/VSS). The [SerenityOS operating
+system](https://github.com/SerenityOS/serenity/commit/53b7f5e6a11e663c83df8030c3171c5945cb75ec)
+has a derived implementation that is inherited by the [Ladybird
+Browser](https://github.com/LadybirdBrowser/ladybird).
 
 The fast_float library provides a performance similar to that of the
 [fast_double_parser](https://github.com/lemire/fast_double_parser) library but
@@ -385,6 +455,14 @@ API more in line with the expectations of C++ programmers. The
 fast_double_parser library is part of the [Microsoft LightGBM machine-learning
 framework](https://github.com/microsoft/LightGBM).
 
+
+
+Packages
+------
+
+[![Packaging status](https://repology.org/badge/vertical-allrepos/fast-float.svg)](https://repology.org/project/fast-float/versions)
+
+
 ## References
 
 * Daniel Lemire, [Number Parsing at a Gigabyte per
@@ -455,7 +533,7 @@ sufficiently recent version of CMake (3.11 or better at least):
 FetchContent_Declare(
   fast_float
   GIT_REPOSITORY https://github.com/fastfloat/fast_float.git
-  GIT_TAG tags/v8.0.1
+  GIT_TAG tags/v8.1.0
   GIT_SHALLOW TRUE)
 
 FetchContent_MakeAvailable(fast_float)
@@ -471,7 +549,7 @@ You may also use [CPM](https://github.com/cpm-cmake/CPM.cmake), like so:
 CPMAddPackage(
   NAME fast_float
   GITHUB_REPOSITORY "fastfloat/fast_float"
-  GIT_TAG v8.0.1)
+  GIT_TAG v8.1.0)
 ```
 
 ## Using as single header
@@ -483,7 +561,7 @@ if desired as described in the command line help.
 
 You may directly download automatically generated single-header files:
 
-<https://github.com/fastfloat/fast_float/releases/download/v8.0.1/fast_float.h>
+<https://github.com/fastfloat/fast_float/releases/download/v8.1.0/fast_float.h>
 
 ## Benchmarking
 
@@ -522,6 +600,7 @@ cmake --build build
   manager](https://conan.io/center/recipes/fast_float).
 * It is part of the [brew package
   manager](https://formulae.brew.sh/formula/fast_float).
+* fast_float is available on [xmake](https://xmake.io) repository.
 * Some Linux distribution like Fedora include fast_float (e.g., as
   `fast_float-devel`).
 
@@ -536,6 +615,11 @@ long digits.
 The library includes code adapted from Google Wuffs (written by Nigel Tao) which
 was originally published under the Apache 2.0 license.
 
+## Stars
+
+
+[![Star History Chart](https://api.star-history.com/svg?repos=fastfloat/fast_float&type=Date)](https://www.star-history.com/#fastfloat/fast_float&Date)
+
 ## License
 
 <sup>

benchmarks/benchmark.cpp

@@ -1,7 +1,7 @@
 #if defined(__linux__) || (__APPLE__ && __aarch64__)
 #define USING_COUNTERS
-#include "event_counter.h"
 #endif
+#include "event_counter.h"
 #include <algorithm>
 #include "fast_float/fast_float.h"
 #include <chrono>

cmake/toolchains-ci/riscv64-linux-gnu.cmake

@@ -0,0 +1,4 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR riscv64)
+
+set(CMAKE_CROSSCOMPILING_EMULATOR "qemu-riscv64-static")

include/fast_float/ascii_number.h

@@ -441,7 +441,7 @@ parse_number_string(UC const *p, UC const *pend,
     if (digit_count > 19) {
       answer.too_many_digits = true;
       // Let us start again, this time, avoiding overflows.
-      // We don't need to check if is_integer, since we use the
+      // We don't need to call if is_integer, since we use the
       // pre-tokenized spans from above.
       i = 0;
       p = answer.integer.ptr;
@@ -451,7 +451,7 @@ parse_number_string(UC const *p, UC const *pend,
         i = i * 10 + uint64_t(*p - UC('0'));
         ++p;
       }
-      if (i >= minimal_nineteen_digit_integer) { // We have a big integers
+      if (i >= minimal_nineteen_digit_integer) { // We have a big integer
         exponent = end_of_integer_part - p + exp_number;
       } else { // We have a value with a fractional component.
         p = answer.fraction.ptr;

include/fast_float/digit_comparison.h

@@ -38,11 +38,8 @@ constexpr static uint64_t powers_of_ten_uint64[] = {1UL,
 // this algorithm is not even close to optimized, but it has no practical
 // effect on performance: in order to have a faster algorithm, we'd need
 // to slow down performance for faster algorithms, and this is still fast.
-template <typename UC>
 fastfloat_really_inline FASTFLOAT_CONSTEXPR14 int32_t
-scientific_exponent(parsed_number_string_t<UC> &num) noexcept {
+scientific_exponent(uint64_t mantissa, int32_t exponent) noexcept {
-  uint64_t mantissa = num.mantissa;
-  int32_t exponent = int32_t(num.exponent);
   while (mantissa >= 10000) {
     mantissa /= 10000;
     exponent += 4;
@@ -398,7 +395,7 @@ inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa negative_digit_comp(
     FASTFLOAT_ASSERT(real_digits.pow2(uint32_t(-pow2_exp)));
   }
 
-  // compare digits, and use it to director rounding
+  // compare digits, and use it to direct rounding
   int ord = real_digits.compare(theor_digits);
   adjusted_mantissa answer = am;
   round<T>(answer, [ord](adjusted_mantissa &a, int32_t shift) {
@@ -419,7 +416,7 @@ inline FASTFLOAT_CONSTEXPR20 adjusted_mantissa negative_digit_comp(
   return answer;
 }
 
-// parse the significant digits as a big integer to unambiguously round the
+// parse the significant digits as a big integer to unambiguously round
 // the significant digits. here, we are trying to determine how to round
 // an extended float representation close to `b+h`, halfway between `b`
 // (the float rounded-down) and `b+u`, the next positive float. this
@@ -438,7 +435,8 @@ digit_comp(parsed_number_string_t<UC> &num, adjusted_mantissa am) noexcept {
   // remove the invalid exponent bias
   am.power2 -= invalid_am_bias;
 
-  int32_t sci_exp = scientific_exponent(num);
+  int32_t sci_exp =
+      scientific_exponent(num.mantissa, static_cast<int32_t>(num.exponent));
   size_t max_digits = binary_format<T>::max_digits();
   size_t digits = 0;
   bigint bigmant;

include/fast_float/fast_float.h

@@ -45,6 +45,38 @@ FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
 from_chars_advanced(UC const *first, UC const *last, T &value,
                     parse_options_t<UC> options) noexcept;
 
+/**
+ * This function multiplies an integer number by a power of 10 and returns
+ * the result as a double precision floating-point value that is correctly
+ * rounded. The resulting floating-point value is the closest floating-point
+ * value, using the "round to nearest, tie to even" convention for values that
+ * would otherwise fall right in-between two values. That is, we provide exact
+ * conversion according to the IEEE standard.
+ *
+ * On overflow infinity is returned, on underflow 0 is returned.
+ *
+ * The implementation does not throw and does not allocate memory (e.g., with
+ * `new` or `malloc`).
+ */
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept;
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept;
+
+/**
+ * This function is a template overload of `integer_times_pow10()`
+ * that returns a floating-point value of type `T` that is one of
+ * supported floating-point types (e.g. `double`, `float`).
+ */
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept;
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept;
+
 /**
  * from_chars for integer types.
  */

include/fast_float/float_common.h

@@ -16,8 +16,8 @@
 #include "constexpr_feature_detect.h"
 
 #define FASTFLOAT_VERSION_MAJOR 8
-#define FASTFLOAT_VERSION_MINOR 0
+#define FASTFLOAT_VERSION_MINOR 1
-#define FASTFLOAT_VERSION_PATCH 1
+#define FASTFLOAT_VERSION_PATCH 0
 
 #define FASTFLOAT_STRINGIZE_IMPL(x) #x
 #define FASTFLOAT_STRINGIZE(x) FASTFLOAT_STRINGIZE_IMPL(x)
@@ -58,6 +58,11 @@ enum class chars_format : uint64_t {
 template <typename UC> struct from_chars_result_t {
   UC const *ptr;
   std::errc ec;
+
+  // https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2497r0.html
+  constexpr explicit operator bool() const noexcept {
+    return ec == std::errc();
+  }
 };
 
 using from_chars_result = from_chars_result_t<char>;
@@ -88,11 +93,12 @@ using parse_options = parse_options_t<char>;
      defined(__MINGW64__) || defined(__s390x__) ||                             \
      (defined(__ppc64__) || defined(__PPC64__) || defined(__ppc64le__) ||      \
       defined(__PPC64LE__)) ||                                                 \
-     defined(__loongarch64))
+     defined(__loongarch64) || (defined(__riscv) && __riscv_xlen == 64))
 #define FASTFLOAT_64BIT 1
 #elif (defined(__i386) || defined(__i386__) || defined(_M_IX86) ||             \
        defined(__arm__) || defined(_M_ARM) || defined(__ppc__) ||              \
-       defined(__MINGW32__) || defined(__EMSCRIPTEN__))
+       defined(__MINGW32__) || defined(__EMSCRIPTEN__) ||                      \
+       (defined(__riscv) && __riscv_xlen == 32))
 #define FASTFLOAT_32BIT 1
 #else
   // Need to check incrementally, since SIZE_MAX is a size_t, avoid overflow.
@@ -400,8 +406,8 @@ full_multiplication(uint64_t a, uint64_t b) {
   // But MinGW on ARM64 doesn't have native support for 64-bit multiplications
   answer.high = __umulh(a, b);
   answer.low = a * b;
-#elif defined(FASTFLOAT_32BIT) ||                                              \
+#elif defined(FASTFLOAT_32BIT) || (defined(_WIN64) && !defined(__clang__) &&   \
-    (defined(_WIN64) && !defined(__clang__) && !defined(_M_ARM64))
+                                   !defined(_M_ARM64) && !defined(__GNUC__))
   answer.low = _umul128(a, b, &answer.high); // _umul128 not available on ARM64
 #elif defined(FASTFLOAT_64BIT) && defined(__SIZEOF_INT128__)
   __uint128_t r = ((__uint128_t)a) * b;
@@ -1126,7 +1132,12 @@ template <typename T> constexpr uint64_t int_luts<T>::min_safe_u64[];
 
 template <typename UC>
 fastfloat_really_inline constexpr uint8_t ch_to_digit(UC c) {
-  return int_luts<>::chdigit[static_cast<unsigned char>(c)];
+  // wchar_t and char can be signed, so we need to be careful.
+  using UnsignedUC = typename std::make_unsigned<UC>::type;
+  return int_luts<>::chdigit[static_cast<unsigned char>(
+      static_cast<UnsignedUC>(c) &
+      static_cast<UnsignedUC>(
+          -((static_cast<UnsignedUC>(c) & ~0xFFull) == 0)))];
 }
 
 fastfloat_really_inline constexpr size_t max_digits_u64(int base) {
@@ -1155,6 +1166,9 @@ static_assert(std::is_same<equiv_uint_t<std::float64_t>, uint64_t>::value,
 static_assert(
     std::numeric_limits<std::float64_t>::is_iec559,
     "std::float64_t must fulfill the requirements of IEC 559 (IEEE 754)");
+
+template <>
+struct binary_format<std::float64_t> : public binary_format<double> {};
 #endif // __STDCPP_FLOAT64_T__
 
 #ifdef __STDCPP_FLOAT32_T__
@@ -1163,6 +1177,9 @@ static_assert(std::is_same<equiv_uint_t<std::float32_t>, uint32_t>::value,
 static_assert(
     std::numeric_limits<std::float32_t>::is_iec559,
     "std::float32_t must fulfill the requirements of IEC 559 (IEEE 754)");
+
+template <>
+struct binary_format<std::float32_t> : public binary_format<float> {};
 #endif // __STDCPP_FLOAT32_T__
 
 #ifdef __STDCPP_FLOAT16_T__
@@ -1234,7 +1251,6 @@ constexpr chars_format adjust_for_feature_macros(chars_format fmt) {
       ;
 }
 } // namespace detail
-
 } // namespace fast_float
 
 #endif

include/fast_float/parse_number.h

@@ -188,32 +188,17 @@ from_chars(UC const *first, UC const *last, T &value,
                                     parse_options_t<UC>(fmt));
 }
 
-/**
+template <typename T>
- * This function overload takes parsed_number_string_t structure that is created
+fastfloat_really_inline FASTFLOAT_CONSTEXPR20 bool
- * and populated either by from_chars_advanced function taking chars range and
+clinger_fast_path_impl(uint64_t mantissa, int64_t exponent, bool is_negative,
- * parsing options or other parsing custom function implemented by user.
+                       T &value) noexcept {
- */
-template <typename T, typename UC>
-FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
-from_chars_advanced(parsed_number_string_t<UC> &pns, T &value) noexcept {
-
-  static_assert(is_supported_float_type<T>::value,
-                "only some floating-point types are supported");
-  static_assert(is_supported_char_type<UC>::value,
-                "only char, wchar_t, char16_t and char32_t are supported");
-
-  from_chars_result_t<UC> answer;
-
-  answer.ec = std::errc(); // be optimistic
-  answer.ptr = pns.lastmatch;
   // The implementation of the Clinger's fast path is convoluted because
   // we want round-to-nearest in all cases, irrespective of the rounding mode
   // selected on the thread.
   // We proceed optimistically, assuming that detail::rounds_to_nearest()
   // returns true.
-  if (binary_format<T>::min_exponent_fast_path() <= pns.exponent &&
+  if (binary_format<T>::min_exponent_fast_path() <= exponent &&
-      pns.exponent <= binary_format<T>::max_exponent_fast_path() &&
+      exponent <= binary_format<T>::max_exponent_fast_path()) {
-      !pns.too_many_digits) {
     // Unfortunately, the conventional Clinger's fast path is only possible
     // when the system rounds to the nearest float.
     //
@@ -224,41 +209,64 @@ from_chars_advanced(parsed_number_string_t<UC> &pns, T &value) noexcept {
     if (!cpp20_and_in_constexpr() && detail::rounds_to_nearest()) {
       // We have that fegetround() == FE_TONEAREST.
       // Next is Clinger's fast path.
-      if (pns.mantissa <= binary_format<T>::max_mantissa_fast_path()) {
+      if (mantissa <= binary_format<T>::max_mantissa_fast_path()) {
-        value = T(pns.mantissa);
+        value = T(mantissa);
-        if (pns.exponent < 0) {
+        if (exponent < 0) {
-          value = value / binary_format<T>::exact_power_of_ten(-pns.exponent);
+          value = value / binary_format<T>::exact_power_of_ten(-exponent);
         } else {
-          value = value * binary_format<T>::exact_power_of_ten(pns.exponent);
+          value = value * binary_format<T>::exact_power_of_ten(exponent);
         }
-        if (pns.negative) {
+        if (is_negative) {
           value = -value;
         }
-        return answer;
+        return true;
       }
     } else {
       // We do not have that fegetround() == FE_TONEAREST.
       // Next is a modified Clinger's fast path, inspired by Jakub Jelínek's
       // proposal
-      if (pns.exponent >= 0 &&
+      if (exponent >= 0 &&
-          pns.mantissa <=
+          mantissa <= binary_format<T>::max_mantissa_fast_path(exponent)) {
-              binary_format<T>::max_mantissa_fast_path(pns.exponent)) {
 #if defined(__clang__) || defined(FASTFLOAT_32BIT)
         // Clang may map 0 to -0.0 when fegetround() == FE_DOWNWARD
-        if (pns.mantissa == 0) {
+        if (mantissa == 0) {
-          value = pns.negative ? T(-0.) : T(0.);
+          value = is_negative ? T(-0.) : T(0.);
-          return answer;
+          return true;
         }
 #endif
-        value = T(pns.mantissa) *
+        value = T(mantissa) * binary_format<T>::exact_power_of_ten(exponent);
-                binary_format<T>::exact_power_of_ten(pns.exponent);
+        if (is_negative) {
-        if (pns.negative) {
           value = -value;
         }
-        return answer;
+        return true;
       }
     }
   }
+  return false;
+}
+
+/**
+ * This function overload takes parsed_number_string_t structure that is created
+ * and populated either by from_chars_advanced function taking chars range and
+ * parsing options or other parsing custom function implemented by user.
+ */
+template <typename T, typename UC>
+FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
+from_chars_advanced(parsed_number_string_t<UC> &pns, T &value) noexcept {
+  static_assert(is_supported_float_type<T>::value,
+                "only some floating-point types are supported");
+  static_assert(is_supported_char_type<UC>::value,
+                "only char, wchar_t, char16_t and char32_t are supported");
+
+  from_chars_result_t<UC> answer;
+
+  answer.ec = std::errc(); // be optimistic
+  answer.ptr = pns.lastmatch;
+
+  if (!pns.too_many_digits &&
+      clinger_fast_path_impl(pns.mantissa, pns.exponent, pns.negative, value))
+    return answer;
+
   adjusted_mantissa am =
       compute_float<binary_format<T>>(pns.exponent, pns.mantissa);
   if (pns.too_many_digits && am.power2 >= 0) {
@@ -336,6 +344,84 @@ from_chars(UC const *first, UC const *last, T &value, int base) noexcept {
   return from_chars_advanced(first, last, value, options);
 }
 
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept {
+  T value;
+  if (clinger_fast_path_impl(mantissa, decimal_exponent, false, value))
+    return value;
+
+  adjusted_mantissa am =
+      compute_float<binary_format<T>>(decimal_exponent, mantissa);
+  to_float(false, am, value);
+  return value;
+}
+
+template <typename T>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value, T>::type
+    integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept {
+  const bool is_negative = mantissa < 0;
+  const uint64_t m = static_cast<uint64_t>(is_negative ? -mantissa : mantissa);
+
+  T value;
+  if (clinger_fast_path_impl(m, decimal_exponent, is_negative, value))
+    return value;
+
+  adjusted_mantissa am = compute_float<binary_format<T>>(decimal_exponent, m);
+  to_float(is_negative, am, value);
+  return value;
+}
+
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(uint64_t mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<double>(mantissa, decimal_exponent);
+}
+
+FASTFLOAT_CONSTEXPR20 inline double
+integer_times_pow10(int64_t mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<double>(mantissa, decimal_exponent);
+}
+
+// the following overloads are here to avoid surprising ambiguity for int,
+// unsigned, etc.
+template <typename T, typename Int>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value &&
+                                std::is_integral<Int>::value &&
+                                !std::is_signed<Int>::value,
+                            T>::type
+    integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<T>(static_cast<uint64_t>(mantissa),
+                                decimal_exponent);
+}
+
+template <typename T, typename Int>
+FASTFLOAT_CONSTEXPR20
+    typename std::enable_if<is_supported_float_type<T>::value &&
+                                std::is_integral<Int>::value &&
+                                std::is_signed<Int>::value,
+                            T>::type
+    integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10<T>(static_cast<int64_t>(mantissa),
+                                decimal_exponent);
+}
+
+template <typename Int>
+FASTFLOAT_CONSTEXPR20 typename std::enable_if<
+    std::is_integral<Int>::value && !std::is_signed<Int>::value, double>::type
+integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10(static_cast<uint64_t>(mantissa), decimal_exponent);
+}
+
+template <typename Int>
+FASTFLOAT_CONSTEXPR20 typename std::enable_if<
+    std::is_integral<Int>::value && std::is_signed<Int>::value, double>::type
+integer_times_pow10(Int mantissa, int decimal_exponent) noexcept {
+  return integer_times_pow10(static_cast<int64_t>(mantissa), decimal_exponent);
+}
+
 template <typename T, typename UC>
 FASTFLOAT_CONSTEXPR20 from_chars_result_t<UC>
 from_chars_int_advanced(UC const *first, UC const *last, T &value,

tests/CMakeLists.txt

@@ -9,8 +9,7 @@ option(FASTFLOAT_SUPPLEMENTAL_TESTS "Run supplemental tests" ON)
 
 if (NOT SYSTEM_DOCTEST)
   FetchContent_Declare(doctest
-    GIT_REPOSITORY https://github.com/onqtam/doctest.git
+    GIT_REPOSITORY https://github.com/lemire/doctest.git)
-    GIT_TAG v2.4.11)
 else ()
   find_package(doctest REQUIRED)
 endif()
@@ -23,24 +22,15 @@ endif()
 
 # FetchContent_MakeAvailable() was only introduced in 3.14
 # https://cmake.org/cmake/help/v3.14/release/3.14.html#modules
-# FetchContent_MakeAvailable(doctest)
 if (NOT SYSTEM_DOCTEST)
-  FetchContent_GetProperties(doctest)
+  FetchContent_MakeAvailable(doctest)
-  if(NOT doctest_POPULATED)
-    FetchContent_Populate(doctest)
-    add_subdirectory(${doctest_SOURCE_DIR} ${doctest_BINARY_DIR})
-  endif()
 endif()
 
 add_library(supplemental-data INTERFACE)
 if (FASTFLOAT_SUPPLEMENTAL_TESTS)
-  FetchContent_GetProperties(supplemental_test_files)
+  message(STATUS "Supplemental tests enabled. Retrieving test files.")
-  if(NOT supplemental_test_files_POPULATED)
+  FetchContent_MakeAvailable(supplemental_test_files)
-    message(STATUS "Supplemental tests enabled. Retrieving test files.")
+  message(STATUS "Supplemental test files retrieved.")
-    FetchContent_Populate(supplemental_test_files)
-    message(STATUS "Supplemental test files retrieved.")
-    add_subdirectory(${supplemental_test_files_SOURCE_DIR} ${supplemental_test_files_BINARY_DIR})
-  endif()
   target_compile_definitions(supplemental-data INTERFACE SUPPLEMENTAL_TEST_DATA_DIR="${supplemental_test_files_BINARY_DIR}/data")
 endif()
 
@@ -71,6 +61,7 @@ fast_float_add_cpp_test(wide_char_test)
 fast_float_add_cpp_test(supported_chars_test)
 fast_float_add_cpp_test(example_test)
 fast_float_add_cpp_test(example_comma_test)
+fast_float_add_cpp_test(example_integer_times_pow10)
 fast_float_add_cpp_test(basictest)
 option(FASTFLOAT_CONSTEXPR_TESTS "Require constexpr tests (build will fail if the compiler won't support it)" OFF)
 if (FASTFLOAT_CONSTEXPR_TESTS)
@@ -82,7 +73,7 @@ endif()
 if (FASTFLOAT_SUPPLEMENTAL_TESTS)
   target_compile_definitions(basictest PRIVATE FASTFLOAT_SUPPLEMENTAL_TESTS)
 endif()
-
+fast_float_add_cpp_test(p2497)
 fast_float_add_cpp_test(long_test)
 fast_float_add_cpp_test(powersoffive_hardround)
 fast_float_add_cpp_test(string_test)

tests/basictest.cpp

@@ -1134,6 +1134,23 @@ TEST_CASE("double.inf") {
          std::errc::result_out_of_range);
   verify("1.9e308", std::numeric_limits<double>::infinity(),
          std::errc::result_out_of_range);
+
+  // DBL_MAX + 0.00000000000000001e308
+  verify("1.79769313486231581e308", std::numeric_limits<double>::infinity(),
+         std::errc::result_out_of_range);
+
+  // DBL_MAX + 0.0000000000000001e308
+  verify("1.7976931348623159e308", std::numeric_limits<double>::infinity(),
+         std::errc::result_out_of_range);
+
+  // ( (2 - 0.5*2^(−52)) * 2^1023 ) smallest number that overflows to infinity
+  verify("179769313486231580793728971405303415079934132710037826936173778980444"
+         "968292764750946649017977587207096330286416692887910946555547851940402"
+         "630657488671505820681908902000708383676273854845817711531764475730270"
+         "069855571366959622842914819860834936475292719074168444365510704342711"
+         "559699508093042880177904174497792",
+         std::numeric_limits<double>::infinity(),
+         std::errc::result_out_of_range);
 }
 
 TEST_CASE("double.general") {
@@ -1143,6 +1160,13 @@ TEST_CASE("double.general") {
   verify("-22250738585072012e-324",
          -0x1p-1022); /* limit between normal and subnormal*/
   verify("-1e-999", -0.0, std::errc::result_out_of_range);
+
+  // DBL_TRUE_MIN / 2
+  verify("2.4703282292062327e-324", 0.0, std::errc::result_out_of_range);
+
+  // DBL_TRUE_MIN / 2 + 0.0000000000000001e-324
+  verify("2.4703282292062328e-324", 0x0.0000000000001p-1022);
+
   verify("-2.2222222222223e-322", -0x1.68p-1069);
   verify("9007199254740993.0", 0x1p+53);
   verify("860228122.6654514319E+90", 0x1.92bb20990715fp+328);
@@ -1318,6 +1342,15 @@ TEST_CASE("double.general") {
       std::numeric_limits<double>::infinity(), std::errc::result_out_of_range);
   verify("-2240084132271013504.131248280843119943687942846658579428",
          -0x1.f1660a65b00bfp+60);
+
+  // ( (2 - 0.5*2^(−52)) * 2^1023 - 1 ) largest 309 decimal digit number
+  // that rounds to DBL_MAX
+  verify("179769313486231580793728971405303415079934132710037826936173778980444"
+         "968292764750946649017977587207096330286416692887910946555547851940402"
+         "630657488671505820681908902000708383676273854845817711531764475730270"
+         "069855571366959622842914819860834936475292719074168444365510704342711"
+         "559699508093042880177904174497791",
+         std::numeric_limits<double>::max());
 }
 
 TEST_CASE("double.decimal_point") {
@@ -1492,14 +1525,35 @@ TEST_CASE("float.inf") {
          std::errc::result_out_of_range);
   verify("3.5028234666e38", std::numeric_limits<float>::infinity(),
          std::errc::result_out_of_range);
+  // FLT_MAX + 0.00000007e38
+  verify("3.40282357e38", std::numeric_limits<float>::infinity(),
+         std::errc::result_out_of_range);
+  // FLT_MAX + 0.0000001e38
+  verify("3.4028236e38", std::numeric_limits<float>::infinity(),
+         std::errc::result_out_of_range);
+
+  // ( (2 - 0.5*2^(-23)) * 2^127 ) smallest number that overflows to infinity
+  verify("340282356779733661637539395458142568448",
+         std::numeric_limits<float>::infinity(),
+         std::errc::result_out_of_range);
 }
 
 TEST_CASE("float.general") {
+  // FLT_TRUE_MIN / 2
+  verify("0.7006492e-45", 0.f, std::errc::result_out_of_range);
+  // FLT_TRUE_MIN / 2 + 0.0000001e-45
+  verify("0.7006493e-45", 0x1p-149f);
+
   // max
   verify("340282346638528859811704183484516925440", 0x1.fffffep+127f);
   // -max
   verify("-340282346638528859811704183484516925440", -0x1.fffffep+127f);
 
+  // ( (2 - 0.5*2^(-23)) * 2^127 - 1 ) largest 39 decimal digits number
+  // that rounds to FLT_MAX
+  verify("340282356779733661637539395458142568447",
+         std::numeric_limits<float>::max());
+
   verify("-1e-999", -0.0f, std::errc::result_out_of_range);
   verify("1."
          "175494140627517859246175898662808184331245864732796240031385942718174"
@@ -2070,3 +2124,317 @@ TEST_CASE("bfloat16.general") {
   //     0.00000000000000000000000000000000000001175494210692441075487029444849287348827052428745893333857174530571588870475618904265502351336181163787841796875bf16);
 }
 #endif
+
+template <typename Int, typename T, typename U>
+void verify_integer_times_pow10_result(Int mantissa, int decimal_exponent,
+                                       T actual, U expected) {
+  static_assert(std::is_same<T, U>::value,
+                "expected and actual types must match");
+
+  INFO("m * 10^e=" << mantissa << " * 10^" << decimal_exponent
+                   << "\n"
+                      "  expected="
+                   << fHexAndDec(expected) << "\n"
+                   << "  ..actual=" << fHexAndDec(actual) << "\n"
+                   << "  expected mantissa="
+                   << iHexAndDec(get_mantissa(expected)) << "\n"
+                   << "  ..actual mantissa=" << iHexAndDec(get_mantissa(actual))
+                   << "\n");
+  CHECK_EQ(actual, expected);
+}
+
+template <typename T, typename Int>
+T calculate_integer_times_pow10_expected_result(Int mantissa,
+                                                int decimal_exponent) {
+  std::string constructed_string =
+      std::to_string(mantissa) + "e" + std::to_string(decimal_exponent);
+  T expected_result;
+  const auto result = fast_float::from_chars(
+      constructed_string.data(),
+      constructed_string.data() + constructed_string.size(), expected_result);
+  if (result.ec != std::errc())
+    INFO("Failed to parse: " << constructed_string);
+  return expected_result;
+}
+
+template <typename Int>
+void verify_integer_times_pow10_dflt(Int mantissa, int decimal_exponent,
+                                     double expected) {
+  static_assert(std::is_integral<Int>::value);
+
+  // the "default" overload
+  const double actual =
+      fast_float::integer_times_pow10(mantissa, decimal_exponent);
+
+  verify_integer_times_pow10_result(mantissa, decimal_exponent, actual,
+                                    expected);
+}
+
+template <typename Int>
+void verify_integer_times_pow10_dflt(Int mantissa, int decimal_exponent) {
+  static_assert(std::is_integral<Int>::value);
+
+  const auto expected_result =
+      calculate_integer_times_pow10_expected_result<double>(mantissa,
+                                                            decimal_exponent);
+
+  verify_integer_times_pow10_dflt(mantissa, decimal_exponent, expected_result);
+}
+
+template <typename T, typename Int>
+void verify_integer_times_pow10(Int mantissa, int decimal_exponent,
+                                T expected) {
+  static_assert(std::is_floating_point<T>::value);
+  static_assert(std::is_integral<Int>::value);
+
+  // explicit specialization
+  const auto actual =
+      fast_float::integer_times_pow10<T>(mantissa, decimal_exponent);
+
+  verify_integer_times_pow10_result(mantissa, decimal_exponent, actual,
+                                    expected);
+}
+
+template <typename T, typename Int>
+void verify_integer_times_pow10(Int mantissa, int decimal_exponent) {
+  static_assert(std::is_floating_point<T>::value);
+  static_assert(std::is_integral<Int>::value);
+
+  const auto expected_result = calculate_integer_times_pow10_expected_result<T>(
+      mantissa, decimal_exponent);
+
+  verify_integer_times_pow10(mantissa, decimal_exponent, expected_result);
+}
+
+namespace all_supported_types {
+template <typename Int>
+void verify_integer_times_pow10(Int mantissa, int decimal_exponent) {
+  static_assert(std::is_integral<Int>::value);
+
+  // verify the "default" overload
+  verify_integer_times_pow10_dflt(mantissa, decimal_exponent);
+
+  // verify explicit specializations
+  ::verify_integer_times_pow10<double>(mantissa, decimal_exponent);
+  ::verify_integer_times_pow10<float>(mantissa, decimal_exponent);
+#if defined(__STDCPP_FLOAT64_T__)
+  ::verify_integer_times_pow10<std::float64_t>(mantissa, decimal_exponent);
+#endif
+#if defined(__STDCPP_FLOAT32_T__)
+  ::verify_integer_times_pow10<std::float32_t>(mantissa, decimal_exponent);
+#endif
+#if defined(__STDCPP_FLOAT16_T__)
+  ::verify_integer_times_pow10<std::float16_t>(mantissa, decimal_exponent);
+#endif
+#if defined(__STDCPP_BFLOAT16_T__)
+  ::verify_integer_times_pow10<std::bfloat16_t>(mantissa, decimal_exponent);
+#endif
+}
+} // namespace all_supported_types
+
+TEST_CASE("integer_times_pow10") {
+  /* explicitly verifying API with different types of integers */
+  // double (the "default" overload)
+  verify_integer_times_pow10_dflt<int8_t>(31, -1, 3.1);
+  verify_integer_times_pow10_dflt<int8_t>(-31, -1, -3.1);
+  verify_integer_times_pow10_dflt<uint8_t>(31, -1, 3.1);
+  verify_integer_times_pow10_dflt<int16_t>(31415, -4, 3.1415);
+  verify_integer_times_pow10_dflt<int16_t>(-31415, -4, -3.1415);
+  verify_integer_times_pow10_dflt<uint16_t>(31415, -4, 3.1415);
+  verify_integer_times_pow10_dflt<int32_t>(314159265, -8, 3.14159265);
+  verify_integer_times_pow10_dflt<int32_t>(-314159265, -8, -3.14159265);
+  verify_integer_times_pow10_dflt<uint32_t>(3141592653, -9, 3.141592653);
+  verify_integer_times_pow10_dflt<long>(314159265, -8, 3.14159265);
+  verify_integer_times_pow10_dflt<long>(-314159265, -8, -3.14159265);
+  verify_integer_times_pow10_dflt<unsigned long>(3141592653, -9, 3.141592653);
+  verify_integer_times_pow10_dflt<int64_t>(3141592653589793238, -18,
+                                           3.141592653589793238);
+  verify_integer_times_pow10_dflt<int64_t>(-3141592653589793238, -18,
+                                           -3.141592653589793238);
+  verify_integer_times_pow10_dflt<uint64_t>(3141592653589793238, -18,
+                                            3.141592653589793238);
+  verify_integer_times_pow10_dflt<long long>(3141592653589793238, -18,
+                                             3.141592653589793238);
+  verify_integer_times_pow10_dflt<long long>(-3141592653589793238, -18,
+                                             -3.141592653589793238);
+  verify_integer_times_pow10_dflt<unsigned long long>(3141592653589793238, -18,
+                                                      3.141592653589793238);
+  // double (explicit specialization)
+  verify_integer_times_pow10<double, int8_t>(31, -1, 3.1);
+  verify_integer_times_pow10<double, int8_t>(-31, -1, -3.1);
+  verify_integer_times_pow10<double, uint8_t>(31, -1, 3.1);
+  verify_integer_times_pow10<double, int16_t>(31415, -4, 3.1415);
+  verify_integer_times_pow10<double, int16_t>(-31415, -4, -3.1415);
+  verify_integer_times_pow10<double, uint16_t>(31415, -4, 3.1415);
+  verify_integer_times_pow10<double, int32_t>(314159265, -8, 3.14159265);
+  verify_integer_times_pow10<double, int32_t>(-314159265, -8, -3.14159265);
+  verify_integer_times_pow10<double, uint32_t>(3141592653, -9, 3.141592653);
+  verify_integer_times_pow10<double, long>(314159265, -8, 3.14159265);
+  verify_integer_times_pow10<double, long>(-314159265, -8, -3.14159265);
+  verify_integer_times_pow10<double, unsigned long>(3141592653, -9,
+                                                    3.141592653);
+  verify_integer_times_pow10<double, int64_t>(3141592653589793238, -18,
+                                              3.141592653589793238);
+  verify_integer_times_pow10<double, int64_t>(-3141592653589793238, -18,
+                                              -3.141592653589793238);
+  verify_integer_times_pow10<double, uint64_t>(3141592653589793238, -18,
+                                               3.141592653589793238);
+  verify_integer_times_pow10<double, long long>(3141592653589793238, -18,
+                                                3.141592653589793238);
+  verify_integer_times_pow10<double, long long>(-3141592653589793238, -18,
+                                                -3.141592653589793238);
+  verify_integer_times_pow10<double, unsigned long long>(
+      3141592653589793238, -18, 3.141592653589793238);
+  // float (explicit specialization)
+  verify_integer_times_pow10<float, int8_t>(31, -1, 3.1f);
+  verify_integer_times_pow10<float, int8_t>(-31, -1, -3.1f);
+  verify_integer_times_pow10<float, uint8_t>(31, -1, 3.1f);
+  verify_integer_times_pow10<float, int16_t>(31415, -4, 3.1415f);
+  verify_integer_times_pow10<float, int16_t>(-31415, -4, -3.1415f);
+  verify_integer_times_pow10<float, uint16_t>(31415, -4, 3.1415f);
+  verify_integer_times_pow10<float, int32_t>(314159265, -8, 3.14159265f);
+  verify_integer_times_pow10<float, int32_t>(-314159265, -8, -3.14159265f);
+  verify_integer_times_pow10<float, uint32_t>(3141592653, -9, 3.14159265f);
+  verify_integer_times_pow10<float, long>(314159265, -8, 3.14159265f);
+  verify_integer_times_pow10<float, long>(-314159265, -8, -3.14159265f);
+  verify_integer_times_pow10<float, unsigned long>(3141592653, -9, 3.14159265f);
+  verify_integer_times_pow10<float, int64_t>(3141592653589793238, -18,
+                                             3.141592653589793238f);
+  verify_integer_times_pow10<float, int64_t>(-3141592653589793238, -18,
+                                             -3.141592653589793238f);
+  verify_integer_times_pow10<float, uint64_t>(3141592653589793238, -18,
+                                              3.141592653589793238f);
+  verify_integer_times_pow10<float, long long>(3141592653589793238, -18,
+                                               3.141592653589793238f);
+  verify_integer_times_pow10<float, long long>(-3141592653589793238, -18,
+                                               -3.141592653589793238f);
+  verify_integer_times_pow10<float, unsigned long long>(
+      3141592653589793238, -18, 3.141592653589793238f);
+
+  for (int mode : {FE_UPWARD, FE_DOWNWARD, FE_TOWARDZERO, FE_TONEAREST}) {
+    fesetround(mode);
+    INFO("fesetround(): " << std::string{round_name(mode)});
+
+    struct Guard {
+      ~Guard() { fesetround(FE_TONEAREST); }
+    } guard;
+
+    namespace all = all_supported_types;
+
+    all::verify_integer_times_pow10(0, 0);
+    all::verify_integer_times_pow10(1, 0);
+    all::verify_integer_times_pow10(0, 1);
+    all::verify_integer_times_pow10(1, 1);
+    all::verify_integer_times_pow10(-1, 0);
+    all::verify_integer_times_pow10(0, -1);
+    all::verify_integer_times_pow10(-1, -1);
+    all::verify_integer_times_pow10(-1, 1);
+    all::verify_integer_times_pow10(1, -1);
+
+    /* denormal min */
+    verify_integer_times_pow10_dflt(49406564584124654, -340,
+                                    std::numeric_limits<double>::denorm_min());
+    verify_integer_times_pow10<double>(
+        49406564584124654, -340, std::numeric_limits<double>::denorm_min());
+    verify_integer_times_pow10<float>(14012984, -52,
+                                      std::numeric_limits<float>::denorm_min());
+
+    /* normal min */
+    verify_integer_times_pow10_dflt(22250738585072014, -324,
+                                    std::numeric_limits<double>::min());
+    verify_integer_times_pow10<double>(22250738585072014, -324,
+                                       std::numeric_limits<double>::min());
+    verify_integer_times_pow10<float>(11754944, -45,
+                                      std::numeric_limits<float>::min());
+
+    /* max */
+    verify_integer_times_pow10_dflt(17976931348623158, 292,
+                                    std::numeric_limits<double>::max());
+    verify_integer_times_pow10<double>(17976931348623158, 292,
+                                       std::numeric_limits<double>::max());
+    verify_integer_times_pow10<float>(34028235, 31,
+                                      std::numeric_limits<float>::max());
+
+    /* underflow */
+    // (DBL_TRUE_MIN / 2) underflows to 0
+    verify_integer_times_pow10_dflt(49406564584124654 / 2, -340, 0.);
+    verify_integer_times_pow10<double>(49406564584124654 / 2, -340, 0.);
+    // (FLT_TRUE_MIN / 2) underflows to 0
+    verify_integer_times_pow10<float>(14012984 / 2, -52, 0.f);
+
+    /* rounding to denormal min */
+    // (DBL_TRUE_MIN / 2 + 0.0000000000000001e-324) rounds to DBL_TRUE_MIN
+    verify_integer_times_pow10_dflt(49406564584124654 / 2 + 1, -340,
+                                    std::numeric_limits<double>::denorm_min());
+    verify_integer_times_pow10<double>(
+        49406564584124654 / 2 + 1, -340,
+        std::numeric_limits<double>::denorm_min());
+    // (FLT_TRUE_MIN / 2 + 0.0000001e-45) rounds to FLT_TRUE_MIN
+    verify_integer_times_pow10<float>(14012984 / 2 + 1, -52,
+                                      std::numeric_limits<float>::denorm_min());
+
+    /* overflow */
+    // (DBL_MAX + 0.0000000000000001e308) overflows to infinity
+    verify_integer_times_pow10_dflt(17976931348623158 + 1, 292,
+                                    std::numeric_limits<double>::infinity());
+    verify_integer_times_pow10<double>(17976931348623158 + 1, 292,
+                                       std::numeric_limits<double>::infinity());
+    // (DBL_MAX + 0.00000000000000001e308) overflows to infinity
+    verify_integer_times_pow10_dflt(179769313486231580 + 1, 291,
+                                    std::numeric_limits<double>::infinity());
+    verify_integer_times_pow10<double>(179769313486231580 + 1, 291,
+                                       std::numeric_limits<double>::infinity());
+    // (FLT_MAX + 0.0000001e38) overflows to infinity
+    verify_integer_times_pow10<float>(34028235 + 1, 31,
+                                      std::numeric_limits<float>::infinity());
+    // (FLT_MAX + 0.00000007e38) overflows to infinity
+    verify_integer_times_pow10<float>(340282350 + 7, 30,
+                                      std::numeric_limits<float>::infinity());
+
+    // loosely verifying correct rounding of 1 to 64 bits
+    // worth of significant digits
+    all::verify_integer_times_pow10(1, 42);
+    all::verify_integer_times_pow10(1, -42);
+    all::verify_integer_times_pow10(12, 42);
+    all::verify_integer_times_pow10(12, -42);
+    all::verify_integer_times_pow10(123, 42);
+    all::verify_integer_times_pow10(123, -42);
+    all::verify_integer_times_pow10(1234, 42);
+    all::verify_integer_times_pow10(1234, -42);
+    all::verify_integer_times_pow10(12345, 42);
+    all::verify_integer_times_pow10(12345, -42);
+    all::verify_integer_times_pow10(123456, 42);
+    all::verify_integer_times_pow10(123456, -42);
+    all::verify_integer_times_pow10(1234567, 42);
+    all::verify_integer_times_pow10(1234567, -42);
+    all::verify_integer_times_pow10(12345678, 42);
+    all::verify_integer_times_pow10(12345678, -42);
+    all::verify_integer_times_pow10(123456789, 42);
+    all::verify_integer_times_pow10(1234567890, 42);
+    all::verify_integer_times_pow10(1234567890, -42);
+    all::verify_integer_times_pow10(12345678901, 42);
+    all::verify_integer_times_pow10(12345678901, -42);
+    all::verify_integer_times_pow10(123456789012, 42);
+    all::verify_integer_times_pow10(123456789012, -42);
+    all::verify_integer_times_pow10(1234567890123, 42);
+    all::verify_integer_times_pow10(1234567890123, -42);
+    all::verify_integer_times_pow10(12345678901234, 42);
+    all::verify_integer_times_pow10(12345678901234, -42);
+    all::verify_integer_times_pow10(123456789012345, 42);
+    all::verify_integer_times_pow10(123456789012345, -42);
+    all::verify_integer_times_pow10(1234567890123456, 42);
+    all::verify_integer_times_pow10(1234567890123456, -42);
+    all::verify_integer_times_pow10(12345678901234567, 42);
+    all::verify_integer_times_pow10(12345678901234567, -42);
+    all::verify_integer_times_pow10(123456789012345678, 42);
+    all::verify_integer_times_pow10(123456789012345678, -42);
+    all::verify_integer_times_pow10(1234567890123456789, 42);
+    all::verify_integer_times_pow10(1234567890123456789, -42);
+    all::verify_integer_times_pow10(12345678901234567890ull, 42);
+    all::verify_integer_times_pow10(12345678901234567890ull, -42);
+    all::verify_integer_times_pow10(std::numeric_limits<int64_t>::max(), 42);
+    all::verify_integer_times_pow10(std::numeric_limits<int64_t>::max(), -42);
+    all::verify_integer_times_pow10(std::numeric_limits<uint64_t>::max(), 42);
+    all::verify_integer_times_pow10(std::numeric_limits<uint64_t>::max(), -42);
+  }
+}

tests/example_integer_times_pow10.cpp

@@ -0,0 +1,36 @@
+#include "fast_float/fast_float.h"
+
+#include <iostream>
+
+void default_overload() {
+  const uint64_t W = 12345678901234567;
+  const int Q = 23;
+  const double result = fast_float::integer_times_pow10(W, Q);
+  std::cout.precision(17);
+  std::cout << W << " * 10^" << Q << " = " << result << " ("
+            << (result == 12345678901234567e23 ? "==" : "!=") << "expected)\n";
+}
+
+void double_specialization() {
+  const uint64_t W = 12345678901234567;
+  const int Q = 23;
+  const double result = fast_float::integer_times_pow10<double>(W, Q);
+  std::cout.precision(17);
+  std::cout << "double: " << W << " * 10^" << Q << " = " << result << " ("
+            << (result == 12345678901234567e23 ? "==" : "!=") << "expected)\n";
+}
+
+void float_specialization() {
+  const uint64_t W = 12345678;
+  const int Q = 23;
+  const float result = fast_float::integer_times_pow10<float>(W, Q);
+  std::cout.precision(9);
+  std::cout << "float: " << W << " * 10^" << Q << " = " << result << " ("
+            << (result == 12345678e23f ? "==" : "!=") << "expected)\n";
+}
+
+int main() {
+  default_overload();
+  double_specialization();
+  float_specialization();
+}

tests/fast_int.cpp

@@ -831,6 +831,275 @@ int main() {
       return EXIT_FAILURE;
     }
   }
+  // dont parse UTF-16 code units of emojis as int if low byte is ascii digit
+  {
+    const std::u16string emojis[] = {
+        u"ℹ", u"ℹ️", u"☸", u"☸️", u"☹", u"☹️", u"✳",  u"✳️",
+        u"✴", u"✴️", u"⤴", u"⤴️", u"⤵", u"⤵️", u"〰", u"〰️",
+    };
+    bool failed = false;
+    auto array_size = sizeof(emojis) / sizeof(emojis[0]);
+    for (size_t i = 0; i < array_size; i++) {
+      auto e = emojis[i];
+      int foo;
+      auto answer = fast_float::from_chars(e.data(), e.data() + e.size(), foo);
+      if (answer.ec == std::errc()) {
+        failed = true;
+        std::cerr << "Incorrectly parsed emoji #" << i << " as integer " << foo
+                  << "." << std::endl;
+      }
+    }
+
+    if (failed) {
+      return EXIT_FAILURE;
+    }
+  }
+  // dont parse UTF-32 code points of emojis as int if low byte is ascii digit
+  {
+    const std::u32string emojis[] = {
+        U"ℹ",
+        U"ℹ️",
+        U"☸",
+        U"☸️",
+        U"☹",
+        U"☹️",
+        U"✳",
+        U"✳️",
+        U"✴",
+        U"✴️",
+        U"⤴",
+        U"⤴️",
+        U"⤵",
+        U"⤵️",
+        U"〰",
+        U"〰️",
+        U"🈲",
+        U"🈳",
+        U"🈴",
+        U"🈵",
+        U"🈶",
+        U"🈷",
+        U"🈷️",
+        U"🈸",
+        U"🈹",
+        U"🌰",
+        U"🌱",
+        U"🌲",
+        U"🌳",
+        U"🌴",
+        U"🌵",
+        U"🌶",
+        U"🌶️",
+        U"🌷",
+        U"🌸",
+        U"🌹",
+        U"🐰",
+        U"🐱",
+        U"🐲",
+        U"🐳",
+        U"🐴",
+        U"🐵",
+        U"🐶",
+        U"🐷",
+        U"🐸",
+        U"🐹",
+        U"🔰",
+        U"🔱",
+        U"🔲",
+        U"🔳",
+        U"🔴",
+        U"🔵",
+        U"🔶",
+        U"🔷",
+        U"🔸",
+        U"🔹",
+        U"😰",
+        U"😱",
+        U"😲",
+        U"😳",
+        U"😴",
+        U"😵",
+        U"😵‍💫",
+        U"😶",
+        U"😶‍🌫",
+        U"😶‍🌫️",
+        U"😷",
+        U"😸",
+        U"😹",
+        U"🤰",
+        U"🤰🏻",
+        U"🤰🏼",
+        U"🤰🏽",
+        U"🤰🏾",
+        U"🤰🏿",
+        U"🤱",
+        U"🤱🏻",
+        U"🤱🏼",
+        U"🤱🏽",
+        U"🤱🏾",
+        U"🤱🏿",
+        U"🤲",
+        U"🤲🏻",
+        U"🤲🏼",
+        U"🤲🏽",
+        U"🤲🏾",
+        U"🤲🏿",
+        U"🤳",
+        U"🤳🏻",
+        U"🤳🏼",
+        U"🤳🏽",
+        U"🤳🏾",
+        U"🤳🏿",
+        U"🤴",
+        U"🤴🏻",
+        U"🤴🏼",
+        U"🤴🏽",
+        U"🤴🏾",
+        U"🤴🏿",
+        U"🤵",
+        U"🤵‍♀",
+        U"🤵‍♀️",
+        U"🤵‍♂",
+        U"🤵‍♂️",
+        U"🤵🏻",
+        U"🤵🏻‍♀",
+        U"🤵🏻‍♀️",
+        U"🤵🏻‍♂",
+        U"🤵🏻‍♂️",
+        U"🤵🏼",
+        U"🤵🏼‍♀",
+        U"🤵🏼‍♀️",
+        U"🤵🏼‍♂",
+        U"🤵🏼‍♂️",
+        U"🤵🏽",
+        U"🤵🏽‍♀",
+        U"🤵🏽‍♀️",
+        U"🤵🏽‍♂",
+        U"🤵🏽‍♂️",
+        U"🤵🏾",
+        U"🤵🏾‍♀",
+        U"🤵🏾‍♀️",
+        U"🤵🏾‍♂",
+        U"🤵🏾‍♂️",
+        U"🤵🏿",
+        U"🤵🏿‍♀",
+        U"🤵🏿‍♀️",
+        U"🤵🏿‍♂",
+        U"🤵🏿‍♂️",
+        U"🤶",
+        U"🤶🏻",
+        U"🤶🏼",
+        U"🤶🏽",
+        U"🤶🏾",
+        U"🤶🏿",
+        U"🤷",
+        U"🤷‍♀",
+        U"🤷‍♀️",
+        U"🤷‍♂",
+        U"🤷‍♂️",
+        U"🤷🏻",
+        U"🤷🏻‍♀",
+        U"🤷🏻‍♀️",
+        U"🤷🏻‍♂",
+        U"🤷🏻‍♂️",
+        U"🤷🏼",
+        U"🤷🏼‍♀",
+        U"🤷🏼‍♀️",
+        U"🤷🏼‍♂",
+        U"🤷🏼‍♂️",
+        U"🤷🏽",
+        U"🤷🏽‍♀",
+        U"🤷🏽‍♀️",
+        U"🤷🏽‍♂",
+        U"🤷🏽‍♂️",
+        U"🤷🏾",
+        U"🤷🏾‍♀",
+        U"🤷🏾‍♀️",
+        U"🤷🏾‍♂",
+        U"🤷🏾‍♂️",
+        U"🤷🏿",
+        U"🤷🏿‍♀",
+        U"🤷🏿‍♀️",
+        U"🤷🏿‍♂",
+        U"🤷🏿‍♂️",
+        U"🤸",
+        U"🤸‍♀",
+        U"🤸‍♀️",
+        U"🤸‍♂",
+        U"🤸‍♂️",
+        U"🤸🏻",
+        U"🤸🏻‍♀",
+        U"🤸🏻‍♀️",
+        U"🤸🏻‍♂",
+        U"🤸🏻‍♂️",
+        U"🤸🏼",
+        U"🤸🏼‍♀",
+        U"🤸🏼‍♀️",
+        U"🤸🏼‍♂",
+        U"🤸🏼‍♂️",
+        U"🤸🏽",
+        U"🤸🏽‍♀",
+        U"🤸🏽‍♀️",
+        U"🤸🏽‍♂",
+        U"🤸🏽‍♂️",
+        U"🤸🏾",
+        U"🤸🏾‍♀",
+        U"🤸🏾‍♀️",
+        U"🤸🏾‍♂",
+        U"🤸🏾‍♂️",
+        U"🤸🏿",
+        U"🤸🏿‍♀",
+        U"🤸🏿‍♀️",
+        U"🤸🏿‍♂",
+        U"🤸🏿‍♂️",
+        U"🤹",
+        U"🤹‍♀",
+        U"🤹‍♀️",
+        U"🤹‍♂",
+        U"🤹‍♂️",
+        U"🤹🏻",
+        U"🤹🏻‍♀",
+        U"🤹🏻‍♀️",
+        U"🤹🏻‍♂",
+        U"🤹🏻‍♂️",
+        U"🤹🏼",
+        U"🤹🏼‍♀",
+        U"🤹🏼‍♀️",
+        U"🤹🏼‍♂",
+        U"🤹🏼‍♂️",
+        U"🤹🏽",
+        U"🤹🏽‍♀",
+        U"🤹🏽‍♀️",
+        U"🤹🏽‍♂",
+        U"🤹🏽‍♂️",
+        U"🤹🏾",
+        U"🤹🏾‍♀",
+        U"🤹🏾‍♀️",
+        U"🤹🏾‍♂",
+        U"🤹🏾‍♂️",
+        U"🤹🏿",
+        U"🤹🏿‍♀",
+        U"🤹🏿‍♀️",
+        U"🤹🏿‍♂",
+        U"🤹🏿‍♂️",
+    };
+    bool failed = false;
+    auto array_size = sizeof(emojis) / sizeof(emojis[0]);
+    for (size_t i = 0; i < array_size; i++) {
+      auto e = emojis[i];
+      int foo;
+      auto answer = fast_float::from_chars(e.data(), e.data() + e.size(), foo);
+      if (answer.ec == std::errc()) {
+        failed = true;
+        std::cerr << "Incorrectly parsed emoji #" << i << " as integer " << foo
+                  << "." << std::endl;
+      }
+    }
+
+    if (failed) {
+      return EXIT_FAILURE;
+    }
+  }
 
   return EXIT_SUCCESS;
 }
@@ -842,4 +1111,4 @@ int main() {
   std::cerr << "The test requires C++17." << std::endl;
   return EXIT_SUCCESS;
 }
-#endif
+#endif

tests/p2497.cpp

@@ -0,0 +1,16 @@
+#include "fast_float/fast_float.h"
+
+#include <iostream>
+#include <string>
+
+int main() {
+  std::string input = "3.1416 xyz ";
+  double result;
+  if (auto answer = fast_float::from_chars(
+          input.data(), input.data() + input.size(), result)) {
+    std::cout << "parsed the number " << result << std::endl;
+    return EXIT_SUCCESS;
+  }
+  std::cerr << "failed to parse " << result << std::endl;
+  return EXIT_FAILURE;
+}