deduction guides for std::valarray
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std::valarray
(C++11)
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Deduction guides (C++17)
Defined in header
<valarray>
template< typename T, std::size_t cnt >
valarray( const T(&)[cnt], std::size_t ) -> valarray<T>;
(since C++17)
valarray( const T(&)[cnt], std::size_t ) -> valarray<T>;
This deduction guide is provided for std::valarray to allow deduction from array and size (note that deduction from pointer and size is covered by the implicit guides).
[edit] Example
Run this code
#include <iostream> #include <valarray> int main() { int a[] = {1, 2, 3, 4}; std::valarray va(a, 3); // uses explicit deduction guide for (int x : va) std::cout << x << ' '; std::cout << '\n'; }
Output:
1 2 3