gnss-sim/3rdparty/boost/url/grammar/detail/tuple.hpp

213 lines
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C++

//
// Copyright (c) 2016-2019 Damian Jarek (damian dot jarek93 at gmail dot com)
// Copyright (c) 2022 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//
#ifndef BOOST_URL_GRAMMAR_DETAIL_TUPLE_HPP
#define BOOST_URL_GRAMMAR_DETAIL_TUPLE_HPP
#include <boost/url/detail/config.hpp>
#include <boost/url/error_types.hpp>
#include <boost/core/empty_value.hpp>
#include <boost/mp11/algorithm.hpp>
#include <boost/mp11/function.hpp>
#include <boost/mp11/integer_sequence.hpp>
#include <boost/type_traits/remove_cv.hpp>
#include <boost/type_traits/copy_cv.hpp>
#include <cstdlib>
#include <utility>
#ifndef BOOST_URL_TUPLE_EBO
// VFALCO No idea what causes it or how to fix it
// https://devblogs.microsoft.com/cppblog/optimizing-the-layout-of-empty-base-classes-in-vs2015-update-2-3/
#ifdef BOOST_MSVC
#define BOOST_URL_TUPLE_EBO 0
#else
#define BOOST_URL_TUPLE_EBO 1
#endif
#endif
namespace boost {
namespace urls {
namespace grammar {
namespace detail {
#if BOOST_URL_TUPLE_EBO
template<std::size_t I, class T>
struct tuple_element_impl
: empty_value<T>
{
constexpr
tuple_element_impl(T const& t)
: empty_value<T>(
empty_init, t)
{
}
constexpr
tuple_element_impl(T&& t)
: empty_value<T>(
empty_init,
std::move(t))
{
}
};
#else
template<std::size_t I, class T>
struct tuple_element_impl
{
T t_;
constexpr
tuple_element_impl(T const& t)
: t_(t)
{
}
constexpr
tuple_element_impl(T&& t)
: t_(std::move(t))
{
}
constexpr
T&
get() noexcept
{
return t_;
}
constexpr
T const&
get() const noexcept
{
return t_;
}
};
#endif
template<std::size_t I, class T>
struct tuple_element_impl<I, T&>
{
T& t;
constexpr
tuple_element_impl(T& t_)
: t(t_)
{
}
T&
get() const noexcept
{
return t;
}
};
template<class... Ts>
struct tuple_impl;
template<class... Ts, std::size_t... Is>
struct tuple_impl<
mp11::index_sequence<Is...>, Ts...>
: tuple_element_impl<Is, Ts>...
{
template<class... Us>
constexpr
explicit
tuple_impl(Us&&... us)
: tuple_element_impl<Is, Ts>(
std::forward<Us>(us))...
{
}
};
template<class... Ts>
struct tuple
: tuple_impl<
mp11::index_sequence_for<Ts...>, Ts...>
{
template<class... Us,
typename std::enable_if<
mp11::mp_bool<
mp11::mp_all<std::is_constructible<
Ts, Us>...>::value &&
! mp11::mp_all<std::is_convertible<
Us, Ts>...>::value>::value,
int>::type = 0
>
constexpr
explicit
tuple(Us&&... us) noexcept
: tuple_impl<mp11::index_sequence_for<
Ts...>, Ts...>{std::forward<Us>(us)...}
{
}
template<class... Us,
typename std::enable_if<
mp11::mp_all<std::is_convertible<
Us, Ts>...>::value,
int>::type = 0
>
constexpr
tuple(Us&&... us) noexcept
: tuple_impl<mp11::index_sequence_for<
Ts...>, Ts...>{std::forward<Us>(us)...}
{
}
};
//------------------------------------------------
template<std::size_t I, class T>
constexpr
T&
get(tuple_element_impl<I, T>& te)
{
return te.get();
}
template<std::size_t I, class T>
constexpr
T const&
get(tuple_element_impl<I, T> const& te)
{
return te.get();
}
template<std::size_t I, class T>
constexpr
T&&
get(tuple_element_impl<I, T>&& te)
{
return std::move(te.get());
}
template<std::size_t I, class T>
constexpr
T&
get(tuple_element_impl<I, T&>&& te)
{
return te.get();
}
template<std::size_t I, class T>
using tuple_element =
typename boost::copy_cv<
mp11::mp_at_c<typename
remove_cv<T>::type,
I>, T>::type;
} // detail
} // grammar
} // urls
} // boost
#endif