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)