Author: Arthur O'Dwyer Date: 2021-08-11T13:40:31-04:00 New Revision: c85a094bcaad233b1a7f029d29f37cfa70ef10c6
URL: https://github.com/llvm/llvm-project/commit/c85a094bcaad233b1a7f029d29f37cfa70ef10c6 DIFF: https://github.com/llvm/llvm-project/commit/c85a094bcaad233b1a7f029d29f37cfa70ef10c6.diff LOG: [libc++] Restore `basic_ios`'s implicit conversion to `bool` in C++03 mode. efriedma noted that D104682 broke this test case, reduced from SPEC2006. #include <istream> bool a(std::istream a) { return a.getline(0,0) == 0; } We can unbreak it by restoring the conversion to something-convertible-to-bool. We chose `void*` in order to match libstdc++. For more ancient history, see PR19460: https://bugs.llvm.org/show_bug.cgi?id=19460 Differential Revision: https://reviews.llvm.org/D107663 (cherry picked from commit c1a8f12873783e8f4827437f6b2dddadfc58109d) Added: Modified: libcxx/include/ios libcxx/test/std/input.output/iostreams.base/ios/iostate.flags/bool.pass.cpp Removed: ################################################################################ diff --git a/libcxx/include/ios b/libcxx/include/ios index 3128bca899990..c9230d6a9484a 100644 --- a/libcxx/include/ios +++ b/libcxx/include/ios @@ -607,8 +607,15 @@ public: static_assert((is_same<_CharT, typename traits_type::char_type>::value), "traits_type::char_type must be the same type as CharT"); +#ifdef _LIBCPP_CXX03_LANG + // Preserve the ability to compare with literal 0, + // and implicitly convert to bool, but not implicitly convert to int. + _LIBCPP_INLINE_VISIBILITY + operator void*() const {return fail() ? nullptr : (void*)this;} +#else _LIBCPP_INLINE_VISIBILITY explicit operator bool() const {return !fail();} +#endif _LIBCPP_INLINE_VISIBILITY bool operator!() const {return fail();} _LIBCPP_INLINE_VISIBILITY iostate rdstate() const {return ios_base::rdstate();} diff --git a/libcxx/test/std/input.output/iostreams.base/ios/iostate.flags/bool.pass.cpp b/libcxx/test/std/input.output/iostreams.base/ios/iostate.flags/bool.pass.cpp index 59896c82f29b9..3fe50c6e045f6 100644 --- a/libcxx/test/std/input.output/iostreams.base/ios/iostate.flags/bool.pass.cpp +++ b/libcxx/test/std/input.output/iostreams.base/ios/iostate.flags/bool.pass.cpp @@ -24,10 +24,16 @@ int main(int, char**) assert(static_cast<bool>(ios) == !ios.fail()); ios.setstate(std::ios::failbit); assert(static_cast<bool>(ios) == !ios.fail()); - static_assert((!std::is_convertible<std::ios, void*>::value), ""); static_assert((!std::is_convertible<std::ios, int>::value), ""); static_assert((!std::is_convertible<std::ios const&, int>::value), ""); - static_assert((!std::is_convertible<std::ios, bool>::value), ""); +#if TEST_STD_VER >= 11 + static_assert(!std::is_convertible<std::ios, void*>::value, ""); + static_assert(!std::is_convertible<std::ios, bool>::value, ""); +#else + static_assert(std::is_convertible<std::ios, void*>::value, ""); + static_assert(std::is_convertible<std::ios, bool>::value, ""); + (void)(ios == 0); // SPEC2006 apparently relies on this to compile +#endif return 0; } _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
