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
This is an older version of Boost and was released in 2015. The current version is 1.89.0.
Occationally the end user may need to provide their own specialization for one of the type traits - typically where intrinsic compiler support is required to implement a specific trait fully. These specializations should derive from boost::true_type or boost::false_type as appropriate:
#include <boost/type_traits/is_pod.hpp> #include <boost/type_traits/is_class.hpp> #include <boost/type_traits/is_union.hpp> struct my_pod{}; struct my_union { char c; int i; }; namespace boost { template<> struct is_pod<my_pod> : public true_type{}; template<> struct is_pod<my_union> : public true_type{}; template<> struct is_union<my_union> : public true_type{}; template<> struct is_class<my_union> : public false_type{}; }