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A container reverse-adaptor for range-based for loops

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  A container reverse-adaptor for range-based for loops Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-19 11:23 +0200
    Re: A container reverse-adaptor for range-based for loops Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-19 12:12 +0200

#81319 — A container reverse-adaptor for range-based for loops

#pragma once
#if defined(__cpp_concepts)	
	#include <concepts>

template<typename Container>
concept concept_reverser = requires( Container cont )
{
	{ cont.rbegin() } -> std::convertible_to<typename 
Container::reverse_iterator>;
	{ cont.rend()   } -> std::convertible_to<typename 
Container::reverse_iterator>;
};
#endif

template<typename Container>
#if defined(__cpp_concepts)	
	requires concept_reverser<Container>
#endif
struct reverser
{
	using iterator = typename Container::reverse_iterator;
	reverser( Container &cont );
	iterator begin();
	iterator end();
private:
	Container &m_cont;
};

template<typename Container>
#if defined(__cpp_concepts)
	requires concept_reverser<Container>
#endif
inline
reverser<Container>::reverser( Container &cont ) :
	m_cont( cont )
{
}

template<typename Container>
#if defined(__cpp_concepts)
	requires concept_reverser<Container>
#endif
inline
typename reverser<Container>::iterator reverser<Container>::begin()
{
	return m_cont.rbegin();
}

template<typename Container>
#if defined(__cpp_concepts)
	requires concept_reverser<Container>
#endif
inline
typename reverser<Container>::iterator reverser<Container>::end()
{
	return m_cont.rend();
}

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#81322

Am 19.09.2021 um 11:23 schrieb Bonita Montero:
> ...
> template<typename Container>
> concept concept_reverser = requires( Container cont )
> {
	typename Container::reverse_iterator;
>      { cont.rbegin() } -> std::convertible_to<typename 
> Container::reverse_iterator>;
>      { cont.rend()   } -> std::convertible_to<typename 
> Container::reverse_iterator>;
> };
> #endif
> ...

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