text: /*=============================================================================
    Copyright (c) 2011-2019 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>
  
  namespace sprout {
  	//
  	// front
  	//
  	//	effect:
  	//		sprout::container_range_traits<Container>::range_front(cont)
  	//		[default]
  	//			ADL callable range_front(cont) -> range_front(cont)
  	//			[default]
  	//				Container is T[N] -> cont[0]
  	//				otherwise, Container is not const
  	//					&& sprout::is_const_reference_cast_convertible<const_reference, reference>
  	//					&& (callable sprout::as_const(cont).front()
  	//						|| callable sprout::as_const(cont).begin()
  	//						|| ADL(without sprout) callable begin(sprout::as_const(cont))
  	//						)
  	//					-> sprout::const_reference_cast<reference>(sprout::front(sprout::as_const(cont)))
  	//				otherwise, callable cont.front() -> cont.front()
  	//				otherwise -> *sprout::begin(cont)
  	//
  	template<typename Container>
  	inline SPROUT_CONSTEXPR typename sprout::container_traits<Container>::reference
  	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
  	front(Container const& cont) {
  		return sprout::container_range_traits<Container const>::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_range_traits<T[N]>::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_range_traits<T const[N]>::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
  