================ @@ -0,0 +1,32 @@ +.. title:: clang-tidy - performance-lost-std-move + +performance-lost-std-move +========================= + +Warns if copy constructor is used instead of std::move() and suggests a fix. +It honours cycles, lambdas, and unspecified call order in compound expressions. + +.. code-block:: c++ + + void f(X); + + void g(X x) { + f(x); // warning: Could be std::move() [performance-lost-std-move] + } + +It finds the last local variable usage, and if it is a copy, emits a warning. +The check is based on pure AST matching and doesn't take into account any data flow information. +Thus, it doesn't catch assign-after-copy cases. +Also it doesn't notice variable references "behind the scenes": + +.. code-block:: c++ + + void f(X); + + void g(X x) { + auto &y = x; + f(x); // emits a warning... + y.f(); // ...but it is still used + } + +Such rare cases should be silenced using `// NOLINT`. ---------------- EugeneZelenko wrote:
Should general functionality be mentioned? https://github.com/llvm/llvm-project/pull/139525 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits