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| -rw-r--r-- | clang/test/Parser/explicit-bool.cpp | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/clang/test/Parser/explicit-bool.cpp b/clang/test/Parser/explicit-bool.cpp new file mode 100644 index 00000000000..bdd91dbbafc --- /dev/null +++ b/clang/test/Parser/explicit-bool.cpp @@ -0,0 +1,62 @@ +// RUN: %clang_cc1 -std=c++17 -verify=cxx17 -Wc++2a-compat %s +// RUN: %clang_cc1 -std=c++2a -verify=cxx2a -Wc++17-compat %s + +namespace disambig { + +// Cases that are valid in C++17 and before, ill-formed in C++20, and that we +// should not treat as explicit(bool) as an extension. +struct A { // cxx2a-note +{{}} + constexpr A() {} + constexpr operator bool() { return true; } + + constexpr explicit (A)(int); // #1 + // cxx17-warning@#1 {{will be parsed as explicit(bool)}} + // cxx2a-error@#1 +{{}} cxx2a-note@#1 +{{}} + // cxx2a-warning@#1 {{incompatible with C++ standards before C++2a}} + + // This is ill-formed (via a DR change), and shouldn't be recognized as a + // constructor (the function declarator cannot be parenthesized in a + // constructor declaration). But accepting it as an extension seems + // reasonable. + // FIXME: Produce an ExtWarn for this. + constexpr explicit (A(float)); // #1b + // cxx17-warning@#1b {{will be parsed as explicit(bool)}} + // cxx2a-error@#1b +{{}} + // cxx2a-warning@#1b {{incompatible with C++ standards before C++2a}} + + explicit (operator int)(); // #2 + // cxx17-warning@#2 {{will be parsed as explicit(bool)}} + // cxx2a-error@#2 +{{}} + // cxx2a-warning@#2 {{incompatible with C++ standards before C++2a}} + + explicit (A::operator float)(); // #2b + // cxx17-warning@#2b {{will be parsed as explicit(bool)}} + // cxx17-error@#2b {{extra qualification on member}} + // cxx2a-error@#2b +{{}} + // cxx2a-warning@#2b {{incompatible with C++ standards before C++2a}} +}; + +constexpr bool operator+(A) { return true; } + +constexpr bool C = false; + +// Cases that should (ideally) be disambiguated as explicit(bool) in earlier +// language modes as an extension. +struct B { + // Looks like a constructor, but not the constructor of B. + explicit (A()) B(); // #3 + // cxx17-warning@#3 {{C++2a extension}} + // cxx2a-warning@#3 {{incompatible with C++ standards before C++2a}} + + // Looks like a 'constructor' of C. Actually a constructor of B. + explicit (C)(B)(A); // #4 + // cxx17-warning@#4 {{C++2a extension}} + // cxx2a-warning@#4 {{incompatible with C++ standards before C++2a}} + + explicit (operator+(A())) operator int(); // #5 + // cxx17-error@#5 {{requires a type specifier}} cxx17-error@#5 {{expected ';'}} + // cxx17-warning@#5 {{will be parsed as explicit(bool)}} + // cxx2a-warning@#5 {{incompatible with C++ standards before C++2a}} +}; + +} |
