From b6dfee2d734a63656dca3d4e844984b393efd83d Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Tue, 15 Dec 2015 21:41:58 +0000
Subject: [PATCH] Fix clang-cl self-host with MSVC 2013 STL std::bind
 implementation

llvm-svn: 255678
---
 llvm/include/llvm/Support/ThreadPool.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/llvm/include/llvm/Support/ThreadPool.h b/llvm/include/llvm/Support/ThreadPool.h
index 85c062179f05..5648db0642af 100644
--- a/llvm/include/llvm/Support/ThreadPool.h
+++ b/llvm/include/llvm/Support/ThreadPool.h
@@ -70,7 +70,12 @@ public:
 #ifndef _MSC_VER
     return asyncImpl(std::move(Task));
 #else
-    return asyncImpl([Task] (VoidTy) -> VoidTy { Task(); return VoidTy(); });
+    // This lambda has to be marked mutable because MSVC 2013's std::bind call
+    // operator isn't const qualified.
+    return asyncImpl([Task](VoidTy) mutable -> VoidTy {
+      Task();
+      return VoidTy();
+    });
 #endif
   }