mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-21 04:42:53 +08:00
23acbfee6a
This code was there to support g++ 4, which didn't support std::is_trivially_constructible and std::is_trivially_copyable. Since we now require g++ >= 9, I think it's fair to assume that GDB will always be compiled with a compiler that supports those. Change-Id: Ie7c1649139a2f48bf662cac92d7f3e38fb1f1ba1
147 lines
4.2 KiB
C++
147 lines
4.2 KiB
C++
/* Copyright (C) 2017-2024 Free Software Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef COMMON_TRAITS_H
|
|
#define COMMON_TRAITS_H
|
|
|
|
#include <type_traits>
|
|
|
|
namespace gdb {
|
|
|
|
/* Implementation of the detection idiom:
|
|
|
|
- http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4502.pdf
|
|
- http://en.cppreference.com/w/cpp/experimental/is_detected
|
|
|
|
*/
|
|
|
|
struct nonesuch
|
|
{
|
|
nonesuch () = delete;
|
|
~nonesuch () = delete;
|
|
nonesuch (const nonesuch &) = delete;
|
|
void operator= (const nonesuch &) = delete;
|
|
};
|
|
|
|
namespace detection_detail {
|
|
/* Implementation of the detection idiom (negative case). */
|
|
template<typename Default, typename AlwaysVoid,
|
|
template<typename...> class Op, typename... Args>
|
|
struct detector
|
|
{
|
|
using value_t = std::false_type;
|
|
using type = Default;
|
|
};
|
|
|
|
/* Implementation of the detection idiom (positive case). */
|
|
template<typename Default, template<typename...> class Op, typename... Args>
|
|
struct detector<Default, std::void_t<Op<Args...>>, Op, Args...>
|
|
{
|
|
using value_t = std::true_type;
|
|
using type = Op<Args...>;
|
|
};
|
|
|
|
/* Detect whether Op<Args...> is a valid type, use Default if not. */
|
|
template<typename Default, template<typename...> class Op,
|
|
typename... Args>
|
|
using detected_or = detector<Default, void, Op, Args...>;
|
|
|
|
/* Op<Args...> if that is a valid type, otherwise Default. */
|
|
template<typename Default, template<typename...> class Op,
|
|
typename... Args>
|
|
using detected_or_t
|
|
= typename detected_or<Default, Op, Args...>::type;
|
|
|
|
} /* detection_detail */
|
|
|
|
template<template<typename...> class Op, typename... Args>
|
|
using is_detected
|
|
= typename detection_detail::detector<nonesuch, void, Op, Args...>::value_t;
|
|
|
|
template<template<typename...> class Op, typename... Args>
|
|
using detected_t
|
|
= typename detection_detail::detector<nonesuch, void, Op, Args...>::type;
|
|
|
|
template<typename Default, template<typename...> class Op, typename... Args>
|
|
using detected_or = detection_detail::detected_or<Default, Op, Args...>;
|
|
|
|
template<typename Default, template<typename...> class Op, typename... Args>
|
|
using detected_or_t = typename detected_or<Default, Op, Args...>::type;
|
|
|
|
template<typename Expected, template<typename...> class Op, typename... Args>
|
|
using is_detected_exact = std::is_same<Expected, detected_t<Op, Args...>>;
|
|
|
|
template<typename To, template<typename...> class Op, typename... Args>
|
|
using is_detected_convertible
|
|
= std::is_convertible<detected_t<Op, Args...>, To>;
|
|
|
|
/* A few trait helpers, mainly stolen from libstdc++. Uppercase
|
|
because "and/or", etc. are reserved keywords. */
|
|
|
|
template<typename Predicate>
|
|
struct Not : public std::integral_constant<bool, !Predicate::value>
|
|
{};
|
|
|
|
template<typename...>
|
|
struct Or;
|
|
|
|
template<>
|
|
struct Or<> : public std::false_type
|
|
{};
|
|
|
|
template<typename B1>
|
|
struct Or<B1> : public B1
|
|
{};
|
|
|
|
template<typename B1, typename B2>
|
|
struct Or<B1, B2>
|
|
: public std::conditional<B1::value, B1, B2>::type
|
|
{};
|
|
|
|
template<typename B1,typename B2,typename B3, typename... Bn>
|
|
struct Or<B1, B2, B3, Bn...>
|
|
: public std::conditional<B1::value, B1, Or<B2, B3, Bn...>>::type
|
|
{};
|
|
|
|
template<typename...>
|
|
struct And;
|
|
|
|
template<>
|
|
struct And<> : public std::true_type
|
|
{};
|
|
|
|
template<typename B1>
|
|
struct And<B1> : public B1
|
|
{};
|
|
|
|
template<typename B1, typename B2>
|
|
struct And<B1, B2>
|
|
: public std::conditional<B1::value, B2, B1>::type
|
|
{};
|
|
|
|
template<typename B1, typename B2, typename B3, typename... Bn>
|
|
struct And<B1, B2, B3, Bn...>
|
|
: public std::conditional<B1::value, And<B2, B3, Bn...>, B1>::type
|
|
{};
|
|
|
|
/* Concepts-light-like helper to make SFINAE logic easier to read. */
|
|
template<typename Condition>
|
|
using Requires = typename std::enable_if<Condition::value, void>::type;
|
|
}
|
|
|
|
#endif /* COMMON_TRAITS_H */
|