cpp-ipc/src/platform/detail.h
2019-09-21 14:21:57 +00:00

150 lines
3.9 KiB
C++
Executable File

#pragma once
#include <memory>
#include <mutex>
#include <shared_mutex>
#include <type_traits>
#include <tuple>
#include <atomic>
#include <algorithm>
#include <utility>
#include <new>
#include "def.h"
#include "export.h"
// pre-defined
#ifdef IPC_UNUSED_
# error "IPC_UNUSED_ has been defined."
#endif
#ifdef IPC_FALLTHROUGH_
# error "IPC_FALLTHROUGH_ has been defined."
#endif
#ifdef IPC_STBIND_
# error "IPC_STBIND_ has been defined."
#endif
#ifdef IPC_CONSTEXPR_
# error "IPC_CONSTEXPR_ has been defined."
#endif
#if __cplusplus >= 201703L
#define IPC_UNUSED_ [[maybe_unused]]
#define IPC_FALLTHROUGH_ [[fallthrough]]
#define IPC_STBIND_(A, B, ...) auto [A, B] = __VA_ARGS__
#define IPC_CONSTEXPR_ constexpr
#else /*__cplusplus < 201703L*/
#if defined(_MSC_VER)
# define IPC_UNUSED_ __pragma(warning(suppress: 4100 4101 4189))
#elif defined(__GNUC__)
# define IPC_UNUSED_ __attribute__((__unused__))
#else
# define IPC_UNUSED_
#endif
#define IPC_FALLTHROUGH_
#define IPC_STBIND_(A, B, ...) \
auto tp___ = __VA_ARGS__ \
auto A = std::get<0>(tp___); \
auto B = std::get<1>(tp___)
#define IPC_CONSTEXPR_ inline
#endif/*__cplusplus < 201703L*/
#if __cplusplus >= 201703L
namespace std {
// deduction guides for std::unique_ptr
template <typename T, typename D>
unique_ptr(T* p, D&& d) -> unique_ptr<T, std::decay_t<D>>;
} // namespace std
namespace ipc {
namespace detail {
using std::unique_ptr;
using std::unique_lock;
using std::shared_lock;
using std::max;
using std::min;
#else /*__cplusplus < 201703L*/
namespace ipc {
namespace detail {
// deduction guides for std::unique_ptr
template <typename T, typename D>
constexpr auto unique_ptr(T* p, D&& d) {
return std::unique_ptr<T, std::decay_t<D>> { p, std::forward<D>(d) };
}
// deduction guides for std::unique_lock
template <typename T>
constexpr auto unique_lock(T&& lc) {
return std::unique_lock<std::decay_t<T>> { std::forward<T>(lc) };
}
// deduction guides for std::shared_lock
template <typename T>
constexpr auto shared_lock(T&& lc) {
return std::shared_lock<std::decay_t<T>> { std::forward<T>(lc) };
}
template <typename T>
constexpr const T& (max)(const T& a, const T& b) {
return (a < b) ? b : a;
}
template <typename T>
constexpr const T& (min)(const T& a, const T& b) {
return (b < a) ? b : a;
}
#endif/*__cplusplus < 201703L*/
template <typename F, typename D>
constexpr decltype(auto) static_switch(std::size_t /*i*/, std::index_sequence<>, F&& /*f*/, D&& def) {
return std::forward<D>(def)();
}
template <typename F, typename D, std::size_t N, std::size_t...I>
constexpr decltype(auto) static_switch(std::size_t i, std::index_sequence<N, I...>, F&& f, D&& def) {
return (i == N) ? std::forward<F>(f)(std::integral_constant<std::size_t, N>{}) :
static_switch(i, std::index_sequence<I...>{}, std::forward<F>(f), std::forward<D>(def));
}
template <std::size_t N, typename F, typename D>
constexpr decltype(auto) static_switch(std::size_t i, F&& f, D&& def) {
return static_switch(i, std::make_index_sequence<N>{}, std::forward<F>(f), std::forward<D>(def));
}
template <typename F, std::size_t...I>
IPC_CONSTEXPR_ void static_for(std::index_sequence<I...>, F&& f) {
IPC_UNUSED_ auto expand = { (std::forward<F>(f)(std::integral_constant<std::size_t, I>{}), 0)... };
}
template <std::size_t N, typename F>
IPC_CONSTEXPR_ void static_for(F&& f) {
static_for(std::make_index_sequence<N>{}, std::forward<F>(f));
}
// Minimum offset between two objects to avoid false sharing.
enum {
// #if __cplusplus >= 201703L
// cache_line_size = std::hardware_destructive_interference_size
// #else /*__cplusplus < 201703L*/
cache_line_size = 64
// #endif/*__cplusplus < 201703L*/
};
} // namespace detail
} // namespace ipc