NAME¶

deductionguidesforstd::array - deductionguidesforstd::array

Synopsis¶

Defined in header <array>
template <class T, class... U> (since C++17)
array(T, U...) -> array<T, 1 + sizeof...(U)>;

One deduction guide is provided for std::array to provide an equivalent of
std::experimental::make_array for construction of std::array from a variadic
parameter pack.

The program is ill-formed if (std::is_same_v<T, U> && ...) is not true. Note that
(std::is_same_v<T, U> && ...) is true when sizeof...(U) is zero.

Example¶

// Run this code

#include <array>
#include <cassert>

int main()
{
int const x = 10;
std::array a{1, 2, 3, 5, x}; // OK, creates std::array<int, 5>
assert(a.back() == x);

// std::array b{1, 2u}; // Error, all arguments must have same type

// std::array<short> c{3, 2, 1}; // Error, wrong number of template args
std::array c(std::to_array<short>({3, 2, 1})); // C++20 alternative, creates std::array<short, 3>
}