diff options
Diffstat (limited to 'lib/Sema/SemaTemplateInstantiate.cpp')
| -rw-r--r-- | lib/Sema/SemaTemplateInstantiate.cpp | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp index 936df1e97d..6814b36ada 100644 --- a/lib/Sema/SemaTemplateInstantiate.cpp +++ b/lib/Sema/SemaTemplateInstantiate.cpp @@ -854,11 +854,14 @@ Sema::InstantiateClassTemplateSpecialization( const TemplateArgumentList *TemplateArgs = &ClassTemplateSpec->getTemplateArgs(); - // C++ [temp.class.spec]p7: - // Partial specialization declarations themselves are not found by - // name lookup. Rather, when the primary template name is used, - // any previously declared partial specializations of the primary - // template are also considered. + // C++ [temp.class.spec.match]p1: + // When a class template is used in a context that requires an + // instantiation of the class, it is necessary to determine + // whether the instantiation is to be generated using the primary + // template or one of the partial specializations. This is done by + // matching the template arguments of the class template + // specialization with the template argument lists of the partial + // specializations. typedef std::pair<ClassTemplatePartialSpecializationDecl *, TemplateArgumentList *> MatchResult; llvm::SmallVector<MatchResult, 4> Matched; @@ -881,13 +884,28 @@ Sema::InstantiateClassTemplateSpecialization( } if (Matched.size() == 1) { + // -- If exactly one matching specialization is found, the + // instantiation is generated from that specialization. Pattern = Matched[0].first; TemplateArgs = Matched[0].second; } else if (Matched.size() > 1) { + // -- If more than one matching specialization is found, the + // partial order rules (14.5.4.2) are used to determine + // whether one of the specializations is more specialized + // than the others. If none of the specializations is more + // specialized than all of the other matching + // specializations, then the use of the class template is + // ambiguous and the program is ill-formed. // FIXME: Implement partial ordering of class template partial // specializations. Diag(ClassTemplateSpec->getLocation(), diag::unsup_template_partial_spec_ordering); + } else { + // -- If no matches are found, the instantiation is generated + // from the primary template. + + // Since we initialized the pattern and template arguments from + // the primary template, there is nothing more we need to do here. } // Note that this is an instantiation. |