From cppreference.com
Defined in header
template<classT>structlogical_and;(until C++14)template<classT=void>structlogical_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.
(C++14)
function object implementing x&&y deducing parameter and return types
(class template specialization)
(since C++14)Member types
Type Definition result_type(deprecated in C++17)(removed in C++20)boolfirst_argument_type(deprecated in C++17)(removed in C++20)Tsecond_argument_type(deprecated in C++17)(removed in C++20)TThese 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()
booloperator()(constT&lhs,constT&rhs)const;(constexpr 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
constexprbooloperator()(constT&lhs,constT&rhs)const{returnlhs&&rhs;}