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c++arraystemplatesstdstdarray

How to declare "using" for "std::array" using template

For example I have code like:

template<typename A, typename B>
using Map = std::map<A, B>;

template<typename A, typename B>
using UnorderedMap = std::unordered_map<A, B>;

I would like to do the same thing for std::array, i.e:

template<typename A, typename B>
using Array = std::array<A, B>;

But if I do this, I will get a compiler error:

error C2993: 'B': illegal type for non-type template parameter '_Size'

error C2955: 'std::array': use of class template requires template

argument list array(21): message : see declaration of 'std::array'

Is there any way to declare an Array that would in the background be using the std::array?

In the end I want to use arrays like Array<int, 7> items instead of std::array<int, 7> items.

Solution

  • The 2nd template parameter of std::array is a non-type template parameter with type std::size_t. It should be

    template<typename A, std::size_t B>
using Array = std::array<A, B>;