static_assert( __cplusplus > 2020'99 );

#pragma once

#include <Alepha/Alepha.h>


namespace Alepha::Hydrogen::Algorithm  ::detail::  identity_m
{
	inline namespace exports
	{
		/*!
		 * Specializable identity function.
		 *
		 * Sometimes you need an unambiguous overload for `std::identity`.  Because the 
		 * standard's version is a function object with an unbounded member template
		 * `operator ()`, this means that deduction contexts cannod deduce which
		 * type is the range and domain for the identity object passed.  Normally
		 * this doesn't matter, but some `Alepha` constructs need to inspect functions.
		 * to that end, one can use `Alepha::Algorithm::identity< T >` for this purpose
		 *
		 * @note This functions effectively the same as the original SGI STL's `identity`
		 * extension, but with C++11's rvalue semantics.  Although we also use a template
		 * variable to avoid the need to instantiate.
		 */
		template< typename T >
		constexpr auto identity= []( T val ) { return val; };
	}
}

namespace Alepha::Hydrogen::Algorithm::inline exports::inline identity_m
{
	using namespace detail::identity_m::exports;
}