Author: rsmith Date: Wed Dec 7 21:24:55 2016 New Revision: 289021 URL: http://llvm.org/viewvc/llvm-project?rev=289021&view=rev Log: [c++1z] P0490R0, NB comment GB 20: if std::tuple_size<T> is complete, use the tuple-like interpretation of decomposition declaration even if there is no ::value member. We already did this, anticipating this resolution, just update comments and tweak a testcase.
Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=289021&r1=289020&r2=289021&view=diff ============================================================================== --- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original) +++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Wed Dec 7 21:24:55 2016 @@ -983,11 +983,8 @@ static IsTupleLike isTupleLike(Sema &S, if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/0)) return IsTupleLike::NotTupleLike; - // FIXME: According to the standard, we're not supposed to diagnose if any - // of the steps below fail (or if lookup for ::value is ambiguous or otherwise - // results in an error), but this is subject to a pending CWG issue / NB - // comment, which says we do diagnose if tuple_size<T> is complete but - // tuple_size<T>::value is not an ICE. + // If we get this far, we've committed to the tuple interpretation, but + // we can still fail if there actually isn't a usable ::value. struct ICEDiagnoser : Sema::VerifyICEDiagnoser { LookupResult &R; Modified: cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp?rev=289021&r1=289020&r2=289021&view=diff ============================================================================== --- cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp (original) +++ cfe/trunk/test/CXX/dcl.decl/dcl.decomp/p3.cpp Wed Dec 7 21:24:55 2016 @@ -10,7 +10,7 @@ void no_tuple_size_1() { auto [x, y] = A namespace std { template<typename T> struct tuple_size; } void no_tuple_size_2() { auto [x, y] = A(); } // ok, decompose elementwise -struct Bad1 {}; +struct Bad1 { int a, b; }; template<> struct std::tuple_size<Bad1> {}; void no_tuple_size_3() { auto [x, y] = Bad1(); } // expected-error {{cannot decompose this type; 'std::tuple_size<Bad1>::value' is not a valid integral constant expression}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits