diff --git a/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp --- a/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp +++ b/clang-tools-extra/clang-tidy/bugprone/ForwardingReferenceOverloadCheck.cpp @@ -58,6 +58,9 @@ return Node.hasDefaultArgument() && TypeMatcher.matches(Node.getDefaultArgument(), Finder, Builder); } +AST_MATCHER(TemplateDecl, hasAssociatedConstraints) { + return Node.hasAssociatedConstraints(); +} } // namespace void ForwardingReferenceOverloadCheck::registerMatchers(MatchFinder *Finder) { @@ -76,6 +79,9 @@ // No warning: enable_if as constructor parameter. parmVarDecl(hasType(isEnableIf())))), unless(hasParent(functionTemplateDecl(anyOf( + // No warning: has associated constraints (like requires + // expression). + hasAssociatedConstraints(), // No warning: enable_if as type parameter. has(templateTypeParmDecl(hasDefaultArgument(isEnableIf()))), // No warning: enable_if as non-type template parameter. diff --git a/clang-tools-extra/docs/clang-tidy/checks/bugprone/forwarding-reference-overload.rst b/clang-tools-extra/docs/clang-tidy/checks/bugprone/forwarding-reference-overload.rst --- a/clang-tools-extra/docs/clang-tidy/checks/bugprone/forwarding-reference-overload.rst +++ b/clang-tools-extra/docs/clang-tidy/checks/bugprone/forwarding-reference-overload.rst @@ -34,6 +34,15 @@ enable_if_t, A&&...>, int> = 0> explicit Person(A&&... a) {} + // C5: perfect forwarding ctor guarded with requires expression + template + requires requires { is_special; } + explicit Person(T&& n) {} + + // C6: perfect forwarding ctor guarded with concept requirement + template + explicit Person(T&& n) {} + // (possibly compiler generated) copy ctor Person(const Person& rhs); }; @@ -42,7 +51,7 @@ constructors. We suppress warnings if the copy and the move constructors are both disabled (deleted or private), because there is nothing the perfect forwarding constructor could hide in this case. We also suppress warnings for constructors -like C3 and C4 that are guarded with an ``enable_if``, assuming the programmer was +like C3-C6 that are guarded with an ``enable_if`` or a concept, assuming the programmer was aware of the possible hiding. Background diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp --- a/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp +++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone/forwarding-reference-overload.cpp @@ -1,4 +1,4 @@ -// RUN: %check_clang_tidy %s bugprone-forwarding-reference-overload %t +// RUN: %check_clang_tidy -std=c++20 %s bugprone-forwarding-reference-overload %t namespace std { template struct enable_if { typedef T type; }; @@ -251,3 +251,20 @@ Test10(T &&Item, E e) : e(e){} }; + +class Test11 { +public: + // Guarded with requires expression. + template + requires requires { just_true; } + Test11(T &&n); +}; + +template +concept JustTrueConcept = requires { just_true; }; + +class Test12 { +public: + // Guarded with concept requirement. + template Test12(T &&n); +};