Implement P0548: 'common_type and duration' This involves a subtle change in the return type of the unary +/- operators for std::chrono::duration, though I expect that no one will notice.

llvm-svn: 298416

2 files changed, 20 insertions, 4 deletions

diff --git a/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_+.pass.cpp b/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_+.pass.cpp
index c0f10147ee8..e4a22cfadfb 100644
--- a/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_+.pass.cpp
+++ b/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_+.pass.cpp
@@ -11,11 +11,13 @@
 
 // duration
 
-// duration operator+() const;
+// constexpr common_type_t<duration> operator+() const;
 
 #include <chrono>
 #include <cassert>
 
+#include <test_macros.h>
+
 int main()
 {
     {
@@ -23,7 +25,7 @@ int main()
     std::chrono::minutes m2 = +m;
     assert(m.count() == m2.count());
     }
-#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+#if TEST_STD_VER >= 11
     {
     constexpr std::chrono::minutes m(3);
     constexpr std::chrono::minutes m2 = +m;
diff --git a/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_-.pass.cpp b/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_-.pass.cpp
index 00da6f69ca5..bc1328c9df5 100644
--- a/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_-.pass.cpp
+++ b/libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_-.pass.cpp
@@ -11,11 +11,13 @@
 
 // duration
 
-// duration operator-() const;
+// constexpr common_type_t<duration> operator-() const;
 
 #include <chrono>
 #include <cassert>
 
+#include <test_macros.h>
+
 int main()
 {
     {
@@ -23,11 +25,23 @@ int main()
     std::chrono::minutes m2 = -m;
     assert(m2.count() == -m.count());
     }
-#ifndef _LIBCPP_HAS_NO_CONSTEXPR
+#if TEST_STD_VER >= 11
     {
     constexpr std::chrono::minutes m(3);
     constexpr std::chrono::minutes m2 = -m;
     static_assert(m2.count() == -m.count(), "");
     }
 #endif
+
+// P0548
+    {
+    typedef std::chrono::duration<int, std::ratio<10,10> > D10;
+    typedef std::chrono::duration<int, std::ratio< 1, 1> > D1;
+    D10 zero{0};
+    D10 one{1};
+    static_assert( (std::is_same< decltype(-one), decltype(zero-one) >::value), "");
+    static_assert( (std::is_same< decltype(zero-one), D1>::value), "");
+    static_assert( (std::is_same< decltype(-one),     D1>::value), "");
+    static_assert( (std::is_same< decltype(+one),     D1>::value), "");
+    }
 }