Author: Niels Dekker Date: 2024-12-03T06:45:06+08:00 New Revision: da5f330e84d74aeacdbb801c46282b9eebec6793
URL: https://github.com/llvm/llvm-project/commit/da5f330e84d74aeacdbb801c46282b9eebec6793 DIFF: https://github.com/llvm/llvm-project/commit/da5f330e84d74aeacdbb801c46282b9eebec6793.diff LOG: [clang-tidy] Adjust size-empty doc because C++11 size() is constant-time (#117629) >From C++11, a conforming `size()` method is guaranteed to be a constant-time function. `empty()` is not _generally_ more efficient than `size()`. It might even be implemented in terms of `size()`. ---- Notes: - Microsoft's STL had implemented `empty()` as `return size() == 0`, until May 2021: https://github.com/microsoft/STL/pull/1836/files - The time complexity of `size()` (specifically for `std::set`) was discussed by the library working group in 2007-2009: https://cplusplus.github.io/LWG/issue632 Added: Modified: clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.h clang-tools-extra/docs/clang-tidy/checks/readability/container-size-empty.rst Removed: ################################################################################ diff --git a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.h b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.h index 617dadce76bd3e..acd8a6bfc50f5e 100644 --- a/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.h +++ b/clang-tools-extra/clang-tidy/readability/ContainerSizeEmptyCheck.h @@ -18,12 +18,10 @@ namespace clang::tidy::readability { /// a call to `empty()`. /// /// The emptiness of a container should be checked using the `empty()` method -/// instead of the `size()` method. It is not guaranteed that `size()` is a -/// constant-time function, and it is generally more efficient and also shows -/// clearer intent to use `empty()`. Furthermore some containers may implement -/// the `empty()` method but not implement the `size()` method. Using `empty()` -/// whenever possible makes it easier to switch to another container in the -/// future. +/// instead of the `size()` method. It shows clearer intent to use `empty()`. +/// Furthermore some containers may implement the `empty()` method but not +/// implement the `size()` method. Using `empty()` whenever possible makes it +/// easier to switch to another container in the future. class ContainerSizeEmptyCheck : public ClangTidyCheck { public: ContainerSizeEmptyCheck(StringRef Name, ClangTidyContext *Context); diff --git a/clang-tools-extra/docs/clang-tidy/checks/readability/container-size-empty.rst b/clang-tools-extra/docs/clang-tidy/checks/readability/container-size-empty.rst index b5abd340b9b2b3..6a007f69767abe 100644 --- a/clang-tools-extra/docs/clang-tidy/checks/readability/container-size-empty.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/readability/container-size-empty.rst @@ -8,12 +8,10 @@ Checks whether a call to the ``size()``/``length()`` method can be replaced with a call to ``empty()``. The emptiness of a container should be checked using the ``empty()`` method -instead of the ``size()``/``length()`` method. It is not guaranteed that -``size()``/``length()`` is a constant-time function, and it is generally more -efficient and also shows clearer intent to use ``empty()``. Furthermore some -containers may implement the ``empty()`` method but not implement the ``size()`` -or ``length()`` method. Using ``empty()`` whenever possible makes it easier to -switch to another container in the future. +instead of the ``size()``/``length()`` method. It shows clearer intent to use +``empty()``. Furthermore some containers may implement the ``empty()`` method +but not implement the ``size()`` or ``length()`` method. Using ``empty()`` +whenever possible makes it easier to switch to another container in the future. The check issues warning if a container has ``empty()`` and ``size()`` or ``length()`` methods matching following signatures: _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
