fork(1) download

copy

#include <type_traits>
#include <array>
 
template<typename... TArgs> struct
contains_only_array_of_3_int
{
	static constexpr bool const value{false};
};
 
template<typename TBack> struct
contains_only_array_of_3_int<TBack>
{
	static constexpr bool const value
	{
		::std::is_same<::std::array<int, 3>, TBack>::value
	};
};
 
template<typename TFront, typename... TRest> struct
contains_only_array_of_3_int<TFront, TRest...>
{
	static constexpr bool const value
	{
		contains_only_array_of_3_int<TFront>::value
		&&
		contains_only_array_of_3_int<TRest...>::value
	};
};
 
template<std::size_t V> class
Test
{
	public:
	Test() {}
 
	template <typename... TArgs>
	Test(TArgs && ... args) 
	{
		static_assert(sizeof...(TArgs) == V, "arguments count mismatch");
		static_assert(contains_only_array_of_3_int<TArgs...>::value, "arguments type mismatch");
	}
};
 
int main()
{
	Test<1> t
	{
		::std::array<int, 3>{ 1, 2, 3 }
	};
	Test<2> t2
	{
		::std::array<int, 3>{ 1, 2, 3 }
	,	::std::array<int, 3>{ 4, 5, 6 }
	};
	Test<3> t3
	{
		::std::array<int, 3>{ 1, 2, 3 }
	,	::std::array<int, 3>{ 4, 5, 6 }
	,	::std::array<int, 3>{ 7, 8, 9 }
	};
	Test<3> t3_args_count_fail
	{
		::std::array<int, 3>{ 1, 2, 3 }
	,	::std::array<int, 3>{ 4, 5, 6 }
	};
	Test<3> t3_args_tupe_fail
	{
		::std::array<int, 3>{ 1, 2, 3 }
	,	::std::array<int, 2>{ 4, 5 }
	,	::std::array<int, 3>{ 7, 8, 9 }
	};
	return(0);
}

prog.cpp: In instantiation of ‘Test<V>::Test(TArgs&& ...) [with TArgs = {std::array<int, 3ul>, std::array<int, 3ul>}; long unsigned int V = 3ul]’:
prog.cpp:65:2:   required from here
prog.cpp:39:3: error: static assertion failed: arguments count mismatch
   static_assert(sizeof...(TArgs) == V, "arguments count mismatch");
   ^~~~~~~~~~~~~
prog.cpp: In instantiation of ‘Test<V>::Test(TArgs&& ...) [with TArgs = {std::array<int, 3ul>, std::array<int, 2ul>, std::array<int, 3ul>}; long unsigned int V = 3ul]’:
prog.cpp:71:2:   required from here
prog.cpp:40:3: error: static assertion failed: arguments type mismatch
   static_assert(contains_only_array_of_3_int<TArgs...>::value, "arguments type mismatch");
   ^~~~~~~~~~~~~

Standard output is empty