Queries the number of elements in a parameter pack.
sizeof...( parameter_pack ) | (since C++11) |
Returns a constant of type std::size_t.
Returns the number of elements in a parameter pack.
#include <iostream>
#include <array>
#include <type_traits>
template<typename... Ts>
constexpr auto make_array(Ts&&... ts)
-> std::array<std::common_type_t<Ts...>,sizeof...(ts)>
{
return { std::forward<Ts>(ts)... };
}
int main()
{
auto b = make_array(1, 2, 3);
std::cout << b.size() << '\n';
for (auto i : b)
std::cout << i << ' ';
}Output:
3 1 2 3
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