Work-in-progress implementation of C++0x [temp.arg.explicit]p9, which

allows an argument pack determines via explicit specification of
function template arguments to be extended by further, deduced
arguments. For example:

template<class ... Types> void f(Types ... values);
void g() { 
  f<int*, float*>(0, 0, 0);   // Types is deduced to the sequence int*, float*, int
}

There are a number of FIXMEs in here that indicate places where we
need to implement + test retained expansions, plus a number of other
places in deduction where we need to correctly cope with the
explicitly-specified arguments when deducing an argument
pack. Furthermore, it appears that the RecursiveASTVisitor needs to be
auditied; it's missing some traversals (especially w.r.t. template
arguments) that cause it not to find unexpanded parameter packs when
it should.

The good news, however, is that the tr1::tuple implementation now
works fully, and the tr1::bind example (both from N2080) is actually
working now. 

llvm-svn: 123163

1 files changed, 7 insertions, 4 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 2c9a4307ed5..f540c7b9358 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -2550,10 +2550,13 @@ bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
   
   // Form argument packs for each of the parameter packs remaining.
   while (Param != ParamEnd) {
+    // If we're checking a partial list of template arguments, don't fill
+    // in arguments for non-template parameter packs.
+    
     if ((*Param)->isTemplateParameterPack()) {     
-      // The parameter pack takes the contents of the current argument pack,
-      // which we built up earlier.
-      if (ArgumentPack.empty()) {
+      if (PartialTemplateArgs && ArgumentPack.empty()) {
+        Converted.push_back(TemplateArgument());
+      } else if (ArgumentPack.empty()) {
         Converted.push_back(TemplateArgument(0, 0));
       } else {
         TemplateArgument *PackedArgs
@@ -3600,7 +3603,7 @@ ExprResult
 Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
                                                   SourceLocation Loc) {
   assert(Arg.getKind() == TemplateArgument::Integral &&
-         "Operation is only value for integral template arguments");
+         "Operation is only valid for integral template arguments");
   QualType T = Arg.getIntegralType();
   if (T->isCharType() || T->isWideCharType())
     return Owned(new (Context) CharacterLiteral(