Implement P0074: Making owner_less more flexible

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@252905 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 69 insertions, 1 deletions

diff --git a/include/memory b/include/memory
index a162eafe6..bd6167268 100644
--- a/include/memory
+++ b/include/memory
@@ -5351,7 +5351,11 @@ weak_ptr<_Tp>::lock() const _NOEXCEPT
     return __r;
 }
 
+#if _LIBCPP_STD_VER > 14
+template <class _Tp = void> struct owner_less;
+#else
 template <class _Tp> struct owner_less;
+#endif
 
 template <class _Tp>
 struct _LIBCPP_TYPE_VIS_ONLY owner_less<shared_ptr<_Tp> >
@@ -5385,6 +5389,30 @@ struct _LIBCPP_TYPE_VIS_ONLY owner_less<weak_ptr<_Tp> >
         {return __x.owner_before(__y);}
 };
 
+#if _LIBCPP_STD_VER > 14
+template <>
+struct _LIBCPP_TYPE_VIS_ONLY owner_less<void>
+{
+    template <class _Tp, class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const
+        {return __x.owner_before(__y);}
+    template <class _Tp, class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()( shared_ptr<_Tp> const& __x,  weak_ptr<_Up> const& __y) const
+        {return __x.owner_before(__y);}
+    template <class _Tp, class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const
+        {return __x.owner_before(__y);}
+    template <class _Tp, class _Up>
+    _LIBCPP_INLINE_VISIBILITY
+    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const
+        {return __x.owner_before(__y);}
+    typedef void is_transparent;
+};
+#endif
+
 template<class _Tp>
 class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this
 {
diff --git a/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp b/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
index d091ae99f..bf1719c66 100644
--- a/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
+++ b/test/std/utilities/memory/util.smartptr/util.smartptr.weak/util.smartptr.ownerless/owner_less.pass.cpp
@@ -30,9 +30,28 @@
 //     bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const;
 //     bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const;
 // };
+// 
+// Added in C++17
+// template<> struct owner_less<void>
+// {
+//     template<class T, class U>
+//         bool operator()(shared_ptr<T> const&, shared_ptr<U> const&) const;
+//     template<class T, class U>
+//         bool operator()(shared_ptr<T> const&, weak_ptr<U> const&) const;
+//     template<class T, class U>
+//         bool operator()(weak_ptr<T> const&, shared_ptr<U> const&) const;
+//     template<class T, class U>
+//         bool operator()(weak_ptr<T> const&, weak_ptr<U> const&) const;
+// 
+//     typedef unspecified is_transparent;
+// };
 
 #include <memory>
 #include <cassert>
+#include <set>
+#include "test_macros.h"
+
+struct X {};
 
 int main()
 {
@@ -79,4 +98,25 @@ int main()
     assert(cs(w1, p3) || cs(w3, p1));
     assert(cs(w3, p1) == cs(w3, p2));
     }
+#if TEST_STD_VER > 14
+    {
+    std::shared_ptr<int> sp1;
+    std::shared_ptr<void> sp2;
+    std::shared_ptr<long> sp3;
+    std::weak_ptr<int> wp1;
+
+    std::owner_less<> cmp;
+    cmp(sp1, sp2);
+    cmp(sp1, wp1);
+    cmp(sp1, sp3);
+    cmp(wp1, sp1);
+    cmp(wp1, wp1);
+    }
+    {
+    // test heterogeneous lookups 
+    std::set<std::shared_ptr<X>, std::owner_less<>> s;
+    std::shared_ptr<void> vp;
+    s.find(vp);
+    }
+#endif
 }
diff --git a/www/cxx1z_status.html b/www/cxx1z_status.html
index be3d5911a..9090af4b9 100644
--- a/www/cxx1z_status.html
+++ b/www/cxx1z_status.html
@@ -75,7 +75,7 @@
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0092R1.html">P0092R1</a></td><td>LWG</td><td>Polishing &lt;chrono&gt;</td><td>Kona</td><td>Complete</td><td>3.8</td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0007R1.html">P0007R1</a></td><td>LWG</td><td>Constant View: A proposal for a <tt>std::as_const</tt> helper function template.</td><td>Kona</td><td>In progress</td><td></td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0156R0.htm" >P0156R0</a></td><td>LWG</td><td>Variadic lock_guard(rev 3).</td><td>Kona</td><td></td><td></td></tr>
-	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0074R0.html">P0074R0</a></td><td>LWG</td><td>Making <tt>std::owner_less</tt> more flexible</td><td>Kona</td><td></td><td></td></tr>
+	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0074R0.html">P0074R0</a></td><td>LWG</td><td>Making <tt>std::owner_less</tt> more flexible</td><td>Kona</td><td>Complete</td><td>3.8</td></tr>
 	<tr><td><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/P0013R1.html">P0013R1</a></td><td>LWG</td><td>Logical type traits rev 2</td><td>Kona</td><td></td><td></td></tr>
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