deduction guides for std::reference_wrapper
< cpp | utility | functional | reference wrapper
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Defined in header
<functional> |
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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.
Example
| This section is incomplete Reason: no example |
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<T> was provided |
removed |
| LWG 2993 | C++17 | defect resolution removed a constructor used for class template argument deduction | added deduction guide to compensate |