Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

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is_class

template <class T>
struct is_class : public true_type-or-false_type {};

Inherits: If T is a (possibly cv-qualified) class type (and not a union type) then inherits from true_type, otherwise inherits from false_type.

C++ Standard Reference: 3.9.2 and 9.2.

Header: #include <boost/type_traits/is_class.hpp> or #include <boost/type_traits.hpp>

Compiler Compatibility: This trait works correctly for almost all current compilers (as of June 2015), with just a minority of older compilers not correctly detecting all the corner cases. You can check the macro BOOST_TT_HAS_CONFORMING_IS_CLASS_IMPLEMENTATION which is defined to 1 when the class works correctly in all cases.

Examples:

Given: class MyClass; then:

is_class<MyClass> inherits from true_type.

is_class<MyClass const>::type is the type true_type.

is_class<MyClass>::value is an integral constant expression that evaluates to true.

is_class<MyClass&>::value is an integral constant expression that evaluates to false.

is_class<MyClass*>::value is an integral constant expression that evaluates to false.

is_class<T>::value_type is the type bool.


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