Sprout/sprout/container/front.hpp
2016-02-25 18:48:28 +09:00

87 lines
3 KiB
C++

/*=============================================================================
Copyright (c) 2011-2016 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
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 SPROUT_CONTAINER_FRONT_HPP
#define SPROUT_CONTAINER_FRONT_HPP
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/container/traits_fwd.hpp>
#include <sprout/container/container_traits.hpp>
#include <sprout/adl/not_found.hpp>
namespace sprout_adl {
sprout::not_found_via_adl range_front(...);
} // namespace sprout_adl
namespace sprout {
namespace container_detail {
template<typename Container>
inline SPROUT_CONSTEXPR typename sprout::container_traits<Container>::reference
range_front(Container& cont) {
return sprout::container_range_traits<Container>::range_front(cont);
}
template<typename Container>
inline SPROUT_CONSTEXPR typename sprout::container_traits<Container const>::reference
range_front(Container const& cont) {
return sprout::container_range_traits<Container>::range_front(cont);
}
} // namespace container_detail
//
// front
//
// effect:
// ADL callable range_front(cont) -> range_front(cont)
// otherwise -> sprout::container_range_traits<Container>::range_front(cont)
// [default]
// callable cont.front() -> cont.front()
// otherwise -> *begin(cont)
//
template<typename Container>
inline SPROUT_CONSTEXPR typename sprout::container_traits<Container>::reference
front(Container& cont) {
using sprout::container_detail::range_front;
using sprout_adl::range_front;
return range_front(cont);
}
template<typename Container>
inline SPROUT_CONSTEXPR typename sprout::container_traits<Container const>::reference
front(Container const& cont) {
using sprout::container_detail::range_front;
using sprout_adl::range_front;
return range_front(cont);
}
template<typename T, std::size_t N>
inline SPROUT_CONSTEXPR typename sprout::container_traits<T[N]>::reference
front(T (& arr)[N]) {
return sprout::container_detail::range_front(arr);
}
template<typename T, std::size_t N>
inline SPROUT_CONSTEXPR typename sprout::container_traits<T const[N]>::reference
front(T const (& arr)[N]) {
return sprout::container_detail::range_front(arr);
}
//
// cfront
//
template<typename Container>
inline SPROUT_CONSTEXPR typename sprout::container_traits<Container const>::reference
cfront(Container const& cont) {
return sprout::front(cont);
}
template<typename T, std::size_t N>
inline SPROUT_CONSTEXPR typename sprout::container_traits<T const[N]>::reference
cfront(T const (& arr)[N]) {
return sprout::front(arr);
}
} // namespace sprout
#include <sprout/container/container_range_traits.hpp>
#endif // #ifndef SPROUT_CONTAINER_FRONT_HPP