Simplify EnableIfSameType

Author: lucic71

cpp2rust/converter/rules/decls.cpp

@@ -300,36 +300,12 @@ clang::QualType EnableIfSameType(const clang::Decl *rule) {
         !type_param->hasDefaultArgument()) {
       continue;
     }
-    auto enable_if = type_param->getDefaultArgument()
-                         .getArgument()
-                         .getAsType()
-                         ->getAs<clang::DependentNameType>();
-    if (!enable_if || enable_if->getQualifier().getKind() !=
-                          clang::NestedNameSpecifier::Kind::Type) {
-      continue;
-    }
-    auto condition_type = enable_if->getQualifier()
-                              .getAsType()
-                              ->getAs<clang::TemplateSpecializationType>();
-    if (!condition_type || condition_type->template_arguments().empty() ||
-        condition_type->template_arguments()[0].getKind() !=
-            clang::TemplateArgument::Expression) {
-      continue;
-    }
-    auto condition = llvm::dyn_cast<clang::DependentScopeDeclRefExpr>(
-        condition_type->template_arguments()[0]
-            .getAsExpr()
-            ->IgnoreParenImpCasts());
-    if (!condition || condition->getQualifier().getKind() !=
-                          clang::NestedNameSpecifier::Kind::Type) {
-      continue;
-    }
-    auto same = condition->getQualifier()
+    auto same = type_param->getDefaultArgument()
+                    .getArgument()
                     .getAsType()
                     ->getAs<clang::TemplateSpecializationType>();
-    if (!same || same->template_arguments().size() != 2 ||
-        same->template_arguments()[1].getKind() !=
-            clang::TemplateArgument::Type) {
+    if (!same || !same->isTypeAlias() ||
+        same->getTemplateName().getAsTemplateDecl()->getName() != "SameAs") {
       continue;
     }
     return same->template_arguments()[1].getAsType();