Scroll to navigation

std::regular(3) C++ Standard Libary std::regular(3)

NAME

std::regular - std::regular

Synopsis


Defined in header <concepts>
template< class T > (since C++20)
concept regular = std::semiregular<T> && std::equality_comparable<T>;


The regular concept specifies that a type is regular, that is, it is copyable,
default constructible, and equality comparable. It is satisfied by types that behave
similarly to built-in types like int, and that are comparable with ==.

Example

// Run this code


#include <concepts>
#include <iostream>


template<std::regular T>
struct Single
{
T value;
friend bool operator==(const Single&, const Single&) = default;
};


int main()
{
Single<int> myInt1{4};
Single<int> myInt2;
myInt2 = myInt1;


if (myInt1 == myInt2)
std::cout << "Equal\n";


std::cout << myInt1.value << ' ' << myInt2.value << '\n';
}

Output:


Equal
4 4

See also


semiregular specifies that an object of a type can be copied, moved, swapped, and
(C++20) default constructed
(concept)

2024.06.10 http://cppreference.com