From ac417faebc02fe301cb2764ff2bdabf9cccfeaa6 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <hhinnant@apple.com>
Date: Sun, 28 Nov 2010 19:41:07 +0000
Subject: [PATCH] Minor fixup in <ratio> and add optional support for
 shared_mutex and upgrade_mutex which must be opted into with #define
 _LIBCPP_SHARED_LOCK

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@120258 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/__mutex_base | 32 ++++++++++++++++++++++++++++++++
 include/ratio        | 20 ++++----------------
 2 files changed, 36 insertions(+), 16 deletions(-)

diff --git a/include/__mutex_base b/include/__mutex_base
index d3b2a1be6..3bc0b5baf 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -18,6 +18,16 @@
 
 #pragma GCC system_header
 
+#ifdef _LIBCPP_SHARED_LOCK
+
+namespace ting {
+template <class> class shared_lock;
+template <class> class upgrade_lock;
+}
+
+#endif  // _LIBCPP_SHARED_LOCK
+
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_VISIBLE mutex
@@ -143,6 +153,28 @@ public:
             __u.__owns_ = false;
             return *this;
         }
+
+#ifdef _LIBCPP_SHARED_LOCK
+
+    unique_lock(ting::shared_lock<mutex_type>&&, try_to_lock_t);
+    template <class _Clock, class _Duration>
+        unique_lock(ting::shared_lock<mutex_type>&&,
+                    const chrono::time_point<_Clock, _Duration>&);
+    template <class _Rep, class _Period>
+        unique_lock(ting::shared_lock<mutex_type>&&,
+                    const chrono::duration<_Rep, _Period>&);
+
+    explicit unique_lock(ting::upgrade_lock<mutex_type>&&);
+    unique_lock(ting::upgrade_lock<mutex_type>&&, try_to_lock_t);
+    template <class _Clock, class _Duration>
+        unique_lock(ting::upgrade_lock<mutex_type>&&,
+                    const chrono::time_point<_Clock, _Duration>&);
+    template <class _Rep, class _Period>
+        unique_lock(ting::upgrade_lock<mutex_type>&&,
+                    const chrono::duration<_Rep, _Period>&);
+
+#endif  // _LIBCPP_SHARED_LOCK
+
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
     void lock();
diff --git a/include/ratio b/include/ratio
index b9b43d838..7369ccf5d 100644
--- a/include/ratio
+++ b/include/ratio
@@ -276,10 +276,7 @@ public:
 
 template <class _R1, class _R2>
 struct _LIBCPP_VISIBLE ratio_multiply
-    : public __ratio_multiply<_R1, _R2>::type
-{
-    typedef typename __ratio_multiply<_R1, _R2>::type type;
-};
+    : public __ratio_multiply<_R1, _R2>::type {};
 
 template <class _R1, class _R2>
 struct __ratio_divide
@@ -297,10 +294,7 @@ public:
 
 template <class _R1, class _R2>
 struct _LIBCPP_VISIBLE ratio_divide
-    : public __ratio_divide<_R1, _R2>::type
-{
-    typedef typename __ratio_divide<_R1, _R2>::type type;
-};
+    : public __ratio_divide<_R1, _R2>::type {};
 
 template <class _R1, class _R2>
 struct __ratio_add
@@ -326,10 +320,7 @@ public:
 
 template <class _R1, class _R2>
 struct _LIBCPP_VISIBLE ratio_add
-    : public __ratio_add<_R1, _R2>::type
-{
-    typedef typename __ratio_add<_R1, _R2>::type type;
-};
+    : public __ratio_add<_R1, _R2>::type {};
 
 template <class _R1, class _R2>
 struct __ratio_subtract
@@ -355,10 +346,7 @@ public:
 
 template <class _R1, class _R2>
 struct _LIBCPP_VISIBLE ratio_subtract
-    : public __ratio_subtract<_R1, _R2>::type
-{
-    typedef typename __ratio_subtract<_R1, _R2>::type type;
-};
+    : public __ratio_subtract<_R1, _R2>::type {};
 
 // ratio_equal