Description:

A concept that is satisfied for types for which boxing is customized to disable unboxing. In other words, types for which a specialization of the type trait BoxTraits exists which declares method Read to have a different return type than T or T&.

See also: IsUnboxable for an alternative concept that satisfied if a type can be unboxed and methods IsType and Unbox do not fail to compile with that type.

Template Parameters

T	The type to check.

Definition at line 358 of file boxingtraits.inl.

Concept definition

template<typename T>
concept IsLocked =
    !std::same_as<T, std::remove_reference_t<decltype(BoxTraits<T>::Read(std::declval<Placeholder>()))> >