deduction guides for std::reference_wrapper

From cppreference.com
 
 
 
Function objects
Function wrappers
(C++11)
(C++11)
(C++17)
Bind
(C++11)
Reference wrappers
(C++11)(C++11)
Operator wrappers
Negators
(deprecated)
(deprecated)

(deprecated)
(deprecated)
Searchers
Old binders and adaptors
(until C++17)
(until C++17)
(until C++17)
(until C++17)
(until C++17)(until C++17)(until C++17)(until C++17)
(until C++17)(until C++17)
(until C++17)(until C++17)

(until C++17)
(until C++17)(until C++17)(until C++17)(until C++17)
 
 
Defined in header <functional>
template<typename T>
reference_wrapper(reference_wrapper<T>) -> reference_wrapper<T>;
(since C++17)

One deduction guide is provided for std::reference_wrapper to make sure reference_wrapper(T&) doesn't beat the copy constructor due to better conversions.

Example