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std::logical_and

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

Function object for performing logical AND (logical conjunction). Effectively calls operator&& on type T.

Specializations

The standard library provides a specialization of std::logical_and when T is not specified, which leaves the parameter types and return type to be deduced.

logical_and<void>

(C++14)

function object implementing x && y deducing argument and return types
(class template specialization)

(since C++14)

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 std::binary_function<T, T, bool>.

(until C++11)

Member functions

operator()

returns the logical AND of the two arguments
(public member function)

std::logical_and::operator()

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 AND of lhs and rhs.

Parameters

lhs, rhs

values to compute logical AND of

Return value

The result of lhs && rhs.

Exceptions

May throw implementation-defined exceptions.

Possible implementation

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

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https://en.cppreference.com/w/cpp/utility/functional/logical_and