When substituting previously-checked template arguments into a template

template parameter that is an expanded parameter pack, only substitute into the
current slice, not the entire pack.

This reduces the checking of N template template arguments for an expanded
parameter pack containing N parameters from quadratic time to linear time in
the length of the pack. This is important because one (and possibly the only?)
general technique for splitting a template parameter pack in linear time
depends on doing this.

llvm-svn: 326973

1 files changed, 6 insertions, 3 deletions

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index e73dbf85feb..65708706d74 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -6362,9 +6362,8 @@ public:
                                    QualType InstantiatedParamType, Expr *Arg,
                                    TemplateArgument &Converted,
                                CheckTemplateArgumentKind CTAK = CTAK_Specified);
-  bool CheckTemplateArgument(TemplateTemplateParmDecl *Param,
-                             TemplateArgumentLoc &Arg,
-                             unsigned ArgumentPackIndex);
+  bool CheckTemplateTemplateArgument(TemplateParameterList *Params,
+                                     TemplateArgumentLoc &Arg);
 
   ExprResult
   BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
@@ -7700,6 +7699,10 @@ public:
   StmtResult SubstStmt(Stmt *S,
                        const MultiLevelTemplateArgumentList &TemplateArgs);
 
+  TemplateParameterList *
+  SubstTemplateParams(TemplateParameterList *Params, DeclContext *Owner,
+                      const MultiLevelTemplateArgumentList &TemplateArgs);
+
   Decl *SubstDecl(Decl *D, DeclContext *Owner,
                   const MultiLevelTemplateArgumentList &TemplateArgs);