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pytorch/c10/util/C++17.h
Yuanyuan Chen 35153d0846 Simplify c10::guts::apply (#164566)
There is only one call site of `c10::guts::apply` that can be replaced by `:std::apply` except for ROCm. This PR therefore simplifies the implementation of `c10::guts::apply`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/164566
Approved by: https://github.com/Aidyn-A, https://github.com/albanD
2025-10-22 00:47:43 +00:00

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2.1 KiB
C++

#pragma once
#ifndef C10_UTIL_CPP17_H_
#define C10_UTIL_CPP17_H_
#include <c10/macros/Macros.h>
#include <functional>
#include <memory>
#include <type_traits>
#include <utility>
#if !defined(__clang__) && !defined(_MSC_VER) && defined(__GNUC__) && \
__GNUC__ < 9
#error \
"You're trying to build PyTorch with a too old version of GCC. We need GCC 9 or later."
#endif
#if defined(__clang__) && __clang_major__ < 9
#error \
"You're trying to build PyTorch with a too old version of Clang. We need Clang 9 or later."
#endif
#if (defined(_MSC_VER) && (!defined(_MSVC_LANG) || _MSVC_LANG < 201703L)) || \
(!defined(_MSC_VER) && __cplusplus < 201703L)
#error You need C++17 to compile PyTorch
#endif
#if defined(_WIN32) && (defined(min) || defined(max))
#error Macro clash with min and max -- define NOMINMAX when compiling your program on Windows
#endif
/*
* This header adds some polyfills with C++17 functionality
*/
namespace c10 {
// std::is_pod is deprecated in C++20, std::is_standard_layout and
// std::is_trivial are introduced in C++11, std::conjunction has been introduced
// in C++17.
template <typename T>
using is_pod = std::conjunction<std::is_standard_layout<T>, std::is_trivial<T>>;
template <typename T>
constexpr bool is_pod_v = is_pod<T>::value;
namespace guts {
#if defined(__HIP__)
// Implementation from http://en.cppreference.com/w/cpp/utility/apply (but
// modified)
// TODO This is an incomplete implementation of std::apply, not working for
// member functions.
namespace detail {
template <class F, class Tuple, std::size_t... INDEX>
C10_HOST_DEVICE constexpr decltype(auto) apply_impl(
F&& f,
Tuple&& t,
std::index_sequence<INDEX...>) {
return std::forward<F>(f)(std::get<INDEX>(std::forward<Tuple>(t))...);
}
} // namespace detail
template <class F, class Tuple>
C10_HOST_DEVICE constexpr decltype(auto) apply(F&& f, Tuple&& t) {
return detail::apply_impl(
std::forward<F>(f),
std::forward<Tuple>(t),
std::make_index_sequence<
std::tuple_size<std::remove_reference_t<Tuple>>::value>{});
}
#endif
} // namespace guts
} // namespace c10
#endif // C10_UTIL_CPP17_H_