Add ring (default) constructor for use with a fixed array type as the…

… container (#33, thanks @Crzyrndm)

include/nonstd/ring.hpp

@@ -48,6 +48,14 @@ class ring
     typedef typename RingSpan::const_reverse_iterator   const_reverse_iterator;
 #endif
 
+#if nsrs_CPP11_OR_GREATER
+    nsrs_REQUIRES_0( !std::is_constructible<Container, size_t>::value )
+    explicit ring()
+        : cont{}
+        , rs( std::begin(cont), std::end(cont) )
+    {}
+#endif
+
     explicit ring( size_type capacity )
         : cont( capacity )
         , rs( cont.begin(), cont.end() )

test/ring-span.t.cpp

@@ -13,6 +13,10 @@
 
 #include nsrs_RING_SPAN_LITE_T_HEADER
 
+#if nsrs_CPP11_OR_GREATER
+# include <array>
+#endif
+
 #include <numeric>
 
 using namespace nonstd;
@@ -1258,6 +1262,17 @@ CASE( "ring: Allows to create data owning ring from container - capacity is powe
 #endif
 }
 
+// issue-33: std::array
+
+CASE( "ring: Allows to create data owning ring from std::array (C++11)" )
+{
+#if nsrs_CPP11_OR_GREATER
+    ring< std::array<int, 3 >> r;
+#else
+    EXPECT( !!"std::array is not available (no C++11)" );
+#endif
+}
+
 CASE( "tweak header: reads tweak header if supported " "[tweak]" )
 {
 #if nsrs_HAVE_TWEAK_HEADER