std::derived_from(3) C++ Standard Libary std::derived_from(3) NAME std::derived_from - std::derived_from Synopsis Defined in header <concepts> template< class Derived, class Base > concept derived_from = std::is_base_of_v<Base, Derived> && (since C++20) std::is_convertible_v<const volatile Derived*, const volatile Base*>; The concept derived_from<Derived, Base> is satisfied if and only if Base is a class type that is either Derived or a public and unambiguous base of Derived, ignoring cv-qualifiers. Note that this behavior is different to std::is_base_of when Base is a private or protected base of Derived. Example // Run this code #include <concepts> class A {}; class B : public A {}; class C : private A {}; // std::derived_from == true only for public inheritance or exact same class static_assert(std::derived_from<B, B> == true); // same class: true static_assert(std::derived_from<int, int> == false); // same primitive type: false static_assert(std::derived_from<B, A> == true); // public inheri- tance: true static_assert(std::derived_from<C, A> == false); // private inheri- tance: false // std::is_base_of == true also for private inheritance static_assert(std::is_base_of_v<B, B> == true); // same class: true static_assert(std::is_base_of_v<int, int> == false); // same primitive type: false static_assert(std::is_base_of_v<A, B> == true); // public inheri- tance: true static_assert(std::is_base_of_v<A, C> == true); // private inheri- tance: true int main() {} See also is_base_of checks if a type is derived from the other type (C++11) (class template) is_convertible is_nothrow_convertible checks if a type can be converted to the other type (C++11) (class template) (C++20) http://cppreference.com 2024.06.10 std::derived_from(3)
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