Implement most of N3638 (return type deduction for normal functions).

Missing (somewhat ironically) is support for the new deduction rules
in lambda functions, plus PCH support for return type patching.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181108 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 5 deletions

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index ee471696bd..688a7360ad 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2868,13 +2868,15 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
     return;
   }
 
-  // C++0x [temp.explicit]p9:
-  //   Except for inline functions, other explicit instantiation declarations
-  //   have the effect of suppressing the implicit instantiation of the entity
-  //   to which they refer.
+  // C++1y [temp.explicit]p10:
+  //   Except for inline functions, declarations with types deduced from their
+  //   initializer or return value, and class template specializations, other
+  //   explicit instantiation declarations have the effect of suppressing the
+  //   implicit instantiation of the entity to which they refer.
   if (Function->getTemplateSpecializationKind()
         == TSK_ExplicitInstantiationDeclaration &&
-      !PatternDecl->isInlined())
+      !PatternDecl->isInlined() &&
+      !PatternDecl->getResultType()->isUndeducedType())
     return;
 
   if (PatternDecl->isInlined())