[clang-doc] avoid unnecessary string casting and concatenatation

Author: hulxv

clang-tools-extra/clang-doc/HTMLGenerator.cpp

@@ -517,10 +517,8 @@ writeFileDefinition(const ClangDocContext &CDCtx, const Location &L) {
   // The links to a specific line in the source code use the github /
   // googlesource notation so it won't work for all hosting pages.
   LocNumberNode->Attributes.emplace_back(
-      "href",
-      (FileURL + formatv("#{0}{1}", CDCtx.RepositoryLinePrefix.value_or(""),
-                         L.LineNumber))
-          .str());
+      "href", formatv("{0}#{1}{2}", FileURL,
+                      CDCtx.RepositoryLinePrefix.value_or(""), L.LineNumber));
   Node->Children.emplace_back(std::move(LocNumberNode));
   Node->Children.emplace_back(std::make_unique<TextNode>(" of file "));
   auto LocFileNode = std::make_unique<TagNode>(

clang-tools-extra/clang-doc/MDGenerator.cpp

@@ -61,9 +61,8 @@ static void writeFileDefinition(const ClangDocContext &CDCtx, const Location &L,
   } else {
 
     OS << formatv("*Defined at [#{0}{1}{2}](#{0}{1}{3})*",
-                  CDCtx.RepositoryLinePrefix.value_or(""),
-                  std::to_string(L.LineNumber), L.Filename,
-                  StringRef{*CDCtx.RepositoryUrl});
+                  CDCtx.RepositoryLinePrefix.value_or(""), L.LineNumber,
+                  L.Filename, *CDCtx.RepositoryUrl);
   }
   OS << "\n\n";
 }