Defined in header <functional> | ||
---|---|---|
template<> class not_equal_to<void>; | (since C++14) |
std::not_equal_to<>
is a specialization of std::not_equal_to
with parameter and return type deduced.
Member types
Member type | Definition |
---|---|
is_transparent | /* unspecified */ |
Member functions
operator() | tests if the two arguments do not compare equal (public member function) |
std::not_equal_to<>::operator()
template< class T, class U> constexpr auto operator()( T&& lhs, U&& rhs ) const -> decltype(std::forward<T>(lhs) != std::forward<U>(rhs)); |
Returns the result of non-equality comparison between lhs
and rhs
.
Parameters
lhs, rhs | - | values to compare |
Return value
The result of lhs != rhs
.
Notes
The member type is_transparent
indicates to the caller that this function object is a transparent function object: it accepts arguments of arbitrary types and uses perfect forwarding, which avoids unnecessary copying and conversion when the function object is used in heterogeneous context, or with rvalue arguments. In particular, template functions such as std::set::find
and std::set::lower_bound
make use of this member type on their Compare
types.
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