Objective-ARC++: infer template type arguments of

ownership-unqualified retainable object type as __strong. This allows
us to write, e.g.,

  std::vector<id>

and we'll infer that the vector's element types have __strong
ownership semantics, which is far nicer than requiring:

  std::vector<__strong id>

Note that we allow one to override the ownership qualifier of a
substituted template type parameter, e.g., given

  template<typename T>
  struct X {
    typedef __weak T type;
  };

X<id> is treated the same as X<__strong id>. At instantiation type,
the __weak in "__weak T" overrides the (inferred or specified)
__strong on the template argument type, so that we can still provide
metaprogramming transformations.

This is part of <rdar://problem/9595486>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133303 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/AST/TemplateBase.cpp b/lib/AST/TemplateBase.cpp
index 6114a5a051..103da1d8a4 100644
--- a/lib/AST/TemplateBase.cpp
+++ b/lib/AST/TemplateBase.cpp
@@ -277,8 +277,10 @@ void TemplateArgument::print(const PrintingPolicy &Policy,
     break;
     
   case Type: {
+    PrintingPolicy SubPolicy(Policy);
+    SubPolicy.SuppressStrongLifetime = true;
     std::string TypeStr;
-    getAsType().getAsStringInternal(TypeStr, Policy);
+    getAsType().getAsStringInternal(TypeStr, SubPolicy);
     Out << TypeStr;
     break;
   }