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