deduction guides for std::array

 

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Containers library

node-handle (C++17)

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array (C++11)

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span (C++20)

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std::array

Member types
Member functions
Element access array::at array::operator[]    array::front array::back array::data Operations array::fill array::swap	Iterators array::beginarray::cbegin array::endarray::cend array::rbeginarray::crbegin    array::rendarray::crend	Capacity array::empty array::size array::max_size
Non-member functions
operator==operator<=> (C++20) get(std::array) swap(std::array) to_array (C++20)	operator|=operator<operator>operator<=operator>= (until C++20)(until C++20)(until C++20)(until C++20)(until C++20)
Helper classes
tuple_size<std::array>
tuple_element<std::array>
Deduction guides(C++17)

 

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 (std::is_same_v<T, U>&& ...) is true when sizeof...(U) is zero.

Example

Run this code

#include <algorithm>#include <array>#include <cassert>#include <type_traits>   int main(){constint 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 the same type   // std::array<short> c{3, 2, 1}; // Error, wrong number of template argsstd::array c{std::to_array<short>({3, 2, 1})};// C++20 facilityassert(std::ranges::equal(c, std::array{3, 2, 1})); static_assert(std::is_same_v<short, decltype(c)::value_type>);}