diff --git a/llvm/docs/CodingStandards.rst b/llvm/docs/CodingStandards.rst index f9685d69ad5d..2ebdfbc91bf6 100644 --- a/llvm/docs/CodingStandards.rst +++ b/llvm/docs/CodingStandards.rst @@ -746,23 +746,21 @@ The convenience of ``auto`` makes it easy to forget that its default behavior is a copy. Particularly in range-based ``for`` loops, careless copies are expensive. -As a rule of thumb, use ``const auto &`` unless you need to mutate or copy the -result, and use ``const auto *`` when copying pointers. +As a rule of thumb, use ``auto &`` unless you need to copy the result, and use +``auto *`` when copying pointers. .. code-block:: c++ - // Typically there's no reason to mutate or modify Val. + // Typically there's no reason to copy. for (const auto &Val : Container) { observe(Val); } - - // Remove the const if you need to modify Val. for (auto &Val : Container) { Val.change(); } // Remove the reference if you really want a new copy. for (auto Val : Container) { Val.change(); saveSomewhere(Val); } // Copy pointers, but make it clear that they're pointers. - for (const auto *Val : Container) { observe(*Val); } - for (auto *Val : Container) { Val->change(); } + for (const auto *Ptr : Container) { observe(*Ptr); } + for (auto *Ptr : Container) { Ptr->change(); } Style Issues ============