std::logical_not
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Defined in header
<functional>
template< class T >
struct logical_not;
(until C++14)
struct logical_not;
template< class T = void >
struct logical_not;
(since C++14)
struct logical_not;
Function object for performing logical NOT (logical negation). Effectively calls operator! for type T.
Contents
[edit] Specializations
The standard library provides a specialization of std::logical_not when T is not specified, which leaves the parameter types and return type to be deduced.
(C++14)
(class template specialization) [edit]
[edit] Member types
Type
Definition
result_type (deprecated in C++17)(removed in C++20)
bool
argument_type (deprecated in C++17)(removed in C++20)
T
These member types are obtained via publicly inheriting std::unary_function <T, bool>.
(until C++11)[edit] Member functions
operator()
(public member function)
std::logical_not::operator()
bool operator()( const T& arg ) const;
(constexpr since C++14)
Returns the logical NOT of arg.
Parameters
arg
-
value to compute logical NOT of
Return value
The result of !arg.
[edit] Exceptions
May throw implementation-defined exceptions.
Possible implementation
constexpr // since C++14 bool operator()(const T& arg) const { return !arg; }