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deduction guides for std::array

From cppreference.com
< cpp‎ | container‎ | array
Defined in header <array>
template <class T, class... U>
array(T, U...) -> array<T, 1 + sizeof...(U)>;
(since C++17)

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 it is true when sizeof...(U) is zero.

[edit] Example

#include <array>
int main()
{
    int const x = 10;
    std::array a{1, 2, 3, 5, x}; // OK, creates std::array<int, 5>
 
//  std::array b{1, 2u}; // Error, all arguments must have same type
}