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
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
template <class T>
struct is_const : public true_type-or-false_type {};
Inherits: If T is a (top level) const-qualified type then inherits from true_type, otherwise inherits from false_type.
C++ Standard Reference: 3.9.3.
Header: #include
<boost/type_traits/is_const.hpp>
or #include <boost/type_traits.hpp>
Examples:
is_const<int const>inherits fromtrue_type.
is_const<int const volatile>::typeis the typetrue_type.
is_const<int* const>::valueis an integral constant expression that evaluates to true.
is_const<int const*>::valueis an integral constant expression that evaluates to false: the const-qualifier is not at the top level in this case.
is_const<int const&>::valueis an integral constant expression that evaluates to false: the const-qualifier is not at the top level in this case.
is_const<int>::valueis an integral constant expression that evaluates to false.
is_const<T>::value_typeis the typebool.