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std::logical_or(3) C++ Standard Libary std::logical_or(3)


std::logical_or - std::logical_or


Defined in header <functional>
template< class T > (until C++14)
struct logical_or;
template< class T = void > (since C++14)
struct logical_or;

Function object for performing logical OR (logical disjunction). Effectively calls
operator|| on type T.


The standard library provides a specialization of std::logical_or when
T is not specified, which leaves the parameter types and return type
to be deduced.
(since C++14)
logical_or<void> function object implementing x || y deducing argument
(C++14) and return types
(class template specialization)

Member types

Type Definition
result_type (deprecated in C++17)(removed in C++20) bool
first_argument_type (deprecated in C++17)(removed in C++20) T
second_argument_type (deprecated in C++17)(removed in C++20) T

These member types are obtained via publicly inheriting (until C++11)
std::binary_function<T, T, bool>.

Member functions

operator() returns the logical OR of the two arguments
(public member function)


bool operator()( const T& lhs, const T& rhs ) const; (until C++14)
constexpr bool operator()( const T& lhs, const T& rhs ) const; (since C++14)

Returns the logical OR of lhs and rhs.


lhs, rhs - values to compute logical OR of

Return value

The result of lhs || rhs.


May throw implementation-defined exceptions.

Possible implementation

constexpr bool operator()(const T &lhs, const T &rhs) const
return lhs || rhs;