|
// Copyright Oliver Kowalke 2014.
|
// 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)
|
|
#ifndef BOOST_CONTEXT_DETAIL_TUPLE_H
|
#define BOOST_CONTEXT_DETAIL_TUPLE_H
|
|
#include <tuple>
|
#include <utility>
|
|
#include <boost/config.hpp>
|
|
#include <boost/context/detail/config.hpp>
|
#include <boost/context/detail/index_sequence.hpp>
|
|
#ifdef BOOST_HAS_ABI_HEADERS
|
# include BOOST_ABI_PREFIX
|
#endif
|
|
namespace boost {
|
namespace context {
|
namespace detail {
|
|
template< typename ... S, typename ... T, std::size_t ... I >
|
void
|
head_impl( std::tuple< S ... > & s,
|
std::tuple< T ... > & t, index_sequence< I ... >) {
|
t = std::tuple< T ... >{ std::get< I >( s) ... };
|
}
|
|
template< typename ... S, typename ... T, std::size_t ... I >
|
void
|
head_impl( std::tuple< S ... > && s,
|
std::tuple< T ... > & t, index_sequence< I ... >) {
|
t = std::tuple< T ... >{ std::get< I >( std::move( s) ) ... };
|
}
|
|
template< typename ... S, std::size_t ... I1, typename ... T, std::size_t ... I2 >
|
void
|
tail_impl( std::tuple< S ... > & s, index_sequence< I1 ... >,
|
std::tuple< T ... > & t, index_sequence< I2 ... >) {
|
constexpr std::size_t Idx = (sizeof...(I1)) - (sizeof...(I2));
|
t = std::tuple< T ... >{ std::get< (Idx + I2) >( s) ... };
|
}
|
|
template< typename ... S, std::size_t ... I1, typename ... T, std::size_t ... I2 >
|
void
|
tail_impl( std::tuple< S ... > && s, index_sequence< I1 ... >,
|
std::tuple< T ... > & t, index_sequence< I2 ... >) {
|
constexpr std::size_t Idx = (sizeof...(I1)) - (sizeof...(I2));
|
t = std::tuple< T ... >{ std::get< (Idx + I2) >( std::move( s) ) ... };
|
}
|
|
template< typename ... T >
|
class tuple_head;
|
|
template< typename ... T >
|
class tuple_head< std::tuple< T ... > > {
|
private:
|
std::tuple< T ... > & t_;
|
|
public:
|
tuple_head( std::tuple< T ... > & t) noexcept :
|
t_( t) {
|
}
|
|
template< typename ... S >
|
void operator=( std::tuple< S ... > & s) {
|
static_assert((sizeof...(T)) <= (sizeof...(S)), "invalid tuple size");
|
head_impl( s,
|
t_, index_sequence_for< T ... >{} );
|
}
|
template< typename ... S >
|
void operator=( std::tuple< S ... > && s) {
|
static_assert((sizeof...(T)) <= (sizeof...(S)), "invalid tuple size");
|
head_impl( std::move( s),
|
t_, index_sequence_for< T ... >{} );
|
}
|
};
|
|
template< typename ... T >
|
class tuple_tail;
|
|
template< typename ... T >
|
class tuple_tail< std::tuple< T ... > > {
|
private:
|
std::tuple< T ... > & t_;
|
|
public:
|
tuple_tail( std::tuple< T ... > & t) noexcept :
|
t_( t) {
|
}
|
|
template< typename ... S >
|
void operator=( std::tuple< S ... > & s) {
|
static_assert((sizeof...(T)) <= (sizeof...(S)), "invalid tuple size");
|
tail_impl( s, index_sequence_for< S ... >{},
|
t_, index_sequence_for< T ... >{} );
|
}
|
|
template< typename ... S >
|
void operator=( std::tuple< S ... > && s) {
|
static_assert((sizeof...(T)) <= (sizeof...(S)), "invalid tuple size");
|
tail_impl( std::move( s), index_sequence_for< S ... >{},
|
t_, index_sequence_for< T ... >{} );
|
}
|
};
|
|
template< typename ... T >
|
detail::tuple_head< std::tuple< T ... > >
|
head( std::tuple< T ... > & tpl) {
|
return tuple_head< std::tuple< T ... > >{ tpl };
|
}
|
|
template< typename ... T >
|
detail::tuple_tail< std::tuple< T ... > >
|
tail( std::tuple< T ... > & tpl) {
|
return tuple_tail< std::tuple< T ... > >{ tpl };
|
}
|
|
}}}
|
|
#ifdef BOOST_HAS_ABI_HEADERS
|
#include BOOST_ABI_SUFFIX
|
#endif
|
|
#endif // BOOST_CONTEXT_DETAIL_TUPLE_H
|
