[PATCH] D69577: [clang-format] [PR35518] C++17 deduction guides are wrongly formatted

[MyDeveloperDay via Phabricator via cfe-commits]

MyDeveloperDay updated this revision to Diff 227062.
MyDeveloperDay added a reviewer: lichray.
MyDeveloperDay added a comment.

Detect deduction guides arrow as a TrailingReturn arrow, allowing use of existing space before/after rules


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D69577/new/

https://reviews.llvm.org/D69577

Files:
  clang/lib/Format/TokenAnnotator.cpp
  clang/unittests/Format/FormatTest.cpp


Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -4977,6 +4977,15 @@
   verifyFormat("void f() { auto a = b->c(); }");
 }
 
+TEST_F(FormatTest, DeductionGuides) {
+  verifyFormat("template <class T> A(const T &, const T &) -> A<T &>;");
+  verifyFormat("template <class T> explicit A(T &, T &&) -> A<T>;");
+  verifyFormat("template <class... Ts> S(Ts...) -> S<Ts...>;");
+  verifyFormat(
+      "template <class... T>\n"
+      "array(T &&... t) -> array<std::common_type_t<T...>, sizeof...(T)>;");
+}
+
 TEST_F(FormatTest, BreaksFunctionDeclarationsWithTrailingTokens) {
   // Avoid breaking before trailing 'const' or other trailing annotations, if
   // they are not function-like.
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -1397,6 +1397,10 @@
                !Current.Previous->is(tok::kw_operator)) {
       // not auto operator->() -> xxx;
       Current.Type = TT_TrailingReturnArrow;
+    } else if (Current.Previous && Current.Previous->is(tok::r_paren) &&
+               Current.startsSequence(tok::arrow, tok::identifier, tok::less)) {
+      // Deduction guides trailing arrow "...) -> A<T>".
+      Current.Type = TT_TrailingReturnArrow;
     } else if (Current.isOneOf(tok::star, tok::amp, tok::ampamp)) {
       Current.Type = determineStarAmpUsage(Current,
                                            Contexts.back().CanBeExpression &&


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D69577.227062.patch
Type: text/x-patch
Size: 1657 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20191030/a3d8c38c/attachment.bin>