Richard, do you think there's anything we could do better here? It seems difficult to support proper move semantic behavior for [Sema]DiagnosticBuilder across the two common use cases:
DiagnosticBuilder D; D << x; D << y; return D; and return DiagnosticBuilder() << x << y; The only thing I can imagine is if every one of those op<< were function templates using universal references (I forget, is that the right name for them?) and matching their return value (so in the first case, passed a non-const lvalue ref, they return by non-const lvalue ref, and in the second case, passed an rvalue, they return the same). But that seems painful. On Tue, Aug 18, 2015 at 1:54 PM, David Blaikie via cfe-commits < cfe-commits@lists.llvm.org> wrote: > Author: dblaikie > Date: Tue Aug 18 15:54:26 2015 > New Revision: 245352 > > URL: http://llvm.org/viewvc/llvm-project?rev=245352&view=rev > Log: > Workaround -Wdeprecated on SemDiagnosticConsumer's tricksy copy ctor. > > Modified: > cfe/trunk/include/clang/Sema/Sema.h > > Modified: cfe/trunk/include/clang/Sema/Sema.h > URL: > http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=245352&r1=245351&r2=245352&view=diff > > ============================================================================== > --- cfe/trunk/include/clang/Sema/Sema.h (original) > +++ cfe/trunk/include/clang/Sema/Sema.h Tue Aug 18 15:54:26 2015 > @@ -1054,6 +1054,14 @@ public: > SemaDiagnosticBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned > DiagID) > : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) { } > > + // This is a cunning lie. DiagnosticBuilder actually performs move > + // construction in its copy constructor (but due to varied uses, it's > not > + // possible to conveniently express this as actual move > construction). So > + // the default copy ctor here is fine, because the base class > disables the > + // source anyway, so the user-defined ~SemaDiagnosticBuilder is a > safe no-op > + // in that case anwyay. > + SemaDiagnosticBuilder(const SemaDiagnosticBuilder&) = default; > + > ~SemaDiagnosticBuilder() { > // If we aren't active, there is nothing to do. > if (!isActive()) return; > > > _______________________________________________ > cfe-commits mailing list > cfe-commits@lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits >
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