std::regular
From cppreference.com
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Concepts library
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regular
(C++20)
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Exposition-only concepts
(C++20)
Defined in header
<concepts>
template< class T >
concept regular = std::semiregular <T> && std::equality_comparable <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 ==.
[edit] 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
[edit] References
- C++23 standard (ISO/IEC 14882:2024):
- 18.6 Object concepts [concepts.object]
- C++20 standard (ISO/IEC 14882:2020):
- 18.6 Object concepts [concepts.object]
[edit] See also
(C++20)
(concept) [edit]