deduction guides for std::reference_wrapper - cppreference.com (original) (raw)
| | | | | ---------------------------------------------------------------------------- | | ------------- | | template< typename T >reference_wrapper( T& ) -> reference_wrapper<T>; | | (since C++17) |
One deduction guide is provided for std::reference_wrapper to support deduction of the sole class template parameter.
[edit] Example
[edit] Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2981 | C++17 | a redundant deduction guide from reference_wrapper was provided | removed |
| LWG 2993 | C++17 | defect resolution removed a constructor used for class template argument deduction | added deduction guide to compensate |