xref: /llvm-project/clang-tools-extra/docs/clang-tidy/checks/cppcoreguidelines/missing-std-forward.rst (revision 0f1f1d45c9f77bf5d8e5dce32551b7c78772b8a6) 
1.. title:: clang-tidy - cppcoreguidelines-missing-std-forward
2
3cppcoreguidelines-missing-std-forward
4=====================================
5
6Warns when a forwarding reference parameter is not forwarded inside the
7function body.
8
9Example:
10
11.. code-block:: c++
12
13  template <class T>
14  void wrapper(T&& t) {
15    impl(std::forward<T>(t), 1, 2); // Correct
16  }
17
18  template <class T>
19  void wrapper2(T&& t) {
20    impl(t, 1, 2); // Oops - should use std::forward<T>(t)
21  }
22
23  template <class T>
24  void wrapper3(T&& t) {
25    impl(std::move(t), 1, 2); // Also buggy - should use std::forward<T>(t)
26  }
27
28  template <class F>
29  void wrapper_function(F&& f) {
30    std::forward<F>(f)(1, 2); // Correct
31  }
32
33  template <class F>
34  void wrapper_function2(F&& f) {
35    f(1, 2); // Incorrect - may not invoke the desired qualified function operator
36  }
37
38This check implements `F.19
39<http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rf-forward>`_
40from the C++ Core Guidelines.
41