template< typename F > struct not_ { typedef unspecified type; };
Returns the result of logical not (!
) operation on its argument.
#include "boost/mpl/not.hpp"
Parameter | Requirement | Description |
---|---|---|
F | A model of nullary Metafunction |
Expression | Expression type | Precondition | Semantics | Postcondition |
---|---|---|---|---|
typedef not_<f>::type c; | A model of bool Integral Constant | Equivalent to typedef bool_<(!f::type::value)> c; |
BOOST_STATIC_ASSERT(not_<true_>::type::value == false); BOOST_STATIC_ASSERT(not_<false_>::type::value == true);