From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 13 Apr 2017 00:14:39 +0000 (+0000)
Subject: Work around MSVC rejects-valid bug related to C++11 narrowing conversions.
X-Git-Tag: llvmorg-5.0.0-rc1~7860
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1f5a05bba183c9630a4a8588deaf5ac0f72f374f;p=platform%2Fupstream%2Fllvm.git

Work around MSVC rejects-valid bug related to C++11 narrowing conversions.

llvm-svn: 300144
---

diff --git a/llvm/include/llvm/Option/ArgList.h b/llvm/include/llvm/Option/ArgList.h
index 91baf4c8..4ed28d7 100644
--- a/llvm/include/llvm/Option/ArgList.h
+++ b/llvm/include/llvm/Option/ArgList.h
@@ -162,6 +162,10 @@ protected:
   // Protect the dtor to ensure this type is never destroyed polymorphically.
   ~ArgList() = default;
 
+  // Implicitly convert a value to an OptSpecifier. Used to work around a bug
+  // in MSVC's implementation of narrowing conversion checking.
+  static OptSpecifier toOptSpecifier(OptSpecifier S) { return S; }
+
 public:
   /// @name Arg Access
   /// @{
@@ -192,21 +196,23 @@ public:
   template<typename ...OptSpecifiers>
   iterator_range<filtered_iterator<sizeof...(OptSpecifiers)>>
   filtered(OptSpecifiers ...Ids) const {
-    OptRange Range = getRange({Ids...});
+    OptRange Range = getRange({toOptSpecifier(Ids)...});
     auto B = Args.begin() + Range.first;
     auto E = Args.begin() + Range.second;
     using Iterator = filtered_iterator<sizeof...(OptSpecifiers)>;
-    return make_range(Iterator(B, E, {Ids...}), Iterator(E, E, {Ids...}));
+    return make_range(Iterator(B, E, {toOptSpecifier(Ids)...}),
+                      Iterator(E, E, {toOptSpecifier(Ids)...}));
   }
 
   template<typename ...OptSpecifiers>
   iterator_range<filtered_reverse_iterator<sizeof...(OptSpecifiers)>>
   filtered_reverse(OptSpecifiers ...Ids) const {
-    OptRange Range = getRange({Ids...});
+    OptRange Range = getRange({toOptSpecifier(Ids)...});
     auto B = Args.rend() - Range.second;
     auto E = Args.rend() - Range.first;
     using Iterator = filtered_reverse_iterator<sizeof...(OptSpecifiers)>;
-    return make_range(Iterator(B, E, {Ids...}), Iterator(E, E, {Ids...}));
+    return make_range(Iterator(B, E, {toOptSpecifier(Ids)...}),
+                      Iterator(E, E, {toOptSpecifier(Ids)...}));
   }
 
   /// @}