clang-tidy/readability/ContainerSizeEmptyCheck.h

0001 //===--- ContainerSizeEmptyCheck.h - clang-tidy -----------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H
0010 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H
0011
0012 #include "../ClangTidyCheck.h"
0013 #include <vector>
0014
0015 namespace clang::tidy::readability {
0016
0017 /// Checks whether a call to the `size()`/`length()` method can be replaced with
0018 /// a call to `empty()`.
0019 ///
0020 /// The emptiness of a container should be checked using the `empty()` method
0021 /// instead of the `size()`/`length()` method. It shows clearer intent to use
0022 /// `empty()`. Furthermore some containers (for example, a `std::forward_list`)
0023 /// may implement the `empty()` method but not implement the `size()` or
0024 /// `length()` method. Using `empty()` whenever possible makes it easier to
0025 /// switch to another container in the future.
0026 class ContainerSizeEmptyCheck : public ClangTidyCheck {
0027 public:
0028   ContainerSizeEmptyCheck(StringRef Name, ClangTidyContext *Context);
0029   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {
0030     return LangOpts.CPlusPlus;
0031   }
0032   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
0033   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
0034   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
0035   std::optional<TraversalKind> getCheckTraversalKind() const override {
0036     return TK_IgnoreUnlessSpelledInSource;
0037   }
0038
0039 private:
0040   std::vector<llvm::StringRef> ExcludedComparisonTypes;
0041 };
0042
0043 } // namespace clang::tidy::readability
0044
0045 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_READABILITY_CONTAINERSIZEEMPTYCHECK_H