Determine if a type T is an instantiation of reference_wrapper. The value static constant will be true if the type T is a specialization of reference_wrapper. boolvaluefalse Contains a reference to an object of type T. reference_wrapper is primarily used to "feed" references to function templates (algorithms) that take their parameter by value. It provides an implicit conversion to T&, which usually allows the function templates to work on references unmodified. Type T. T T & Does not throw. The stored reference. T & Does not throw. The stored reference. T * Does not throw. A pointer to the object referenced by the stored reference. T &Constructs a reference_wrapper object that stores a reference to t.Does not throw. T &&Construction from a temporary object is disabled. Find the type in a reference_wrapper. The typedef type is T::type if T is a reference_wrapper, T otherwise. T reference_wrapper< T > constT & Does not throw. reference_wrapper<T>(t) reference_wrapper< T const > constT const & Does not throw. reference_wrapper<T const>(t) voidT const &&Construction from a temporary object is disabled. voidT const &&Construction from a temporary object is disabled. unwrap_reference< T >::type &T & Does not throw. unwrap_reference<T>::type&(t)