catch_tostring: toString for std::tuple

include/internal/catch_tostring.h

@@ -193,6 +193,50 @@ struct StringMaker<std::vector<T, Allocator> > {
     }
 };
 
+
+#ifdef CATCH_CPP11_OR_GREATER
+  /*
+    toString for tuples
+  */
+namespace TupleDetail {
+  template<
+      typename Tuple,
+      std::size_t N = 0,
+      bool = (N < std::tuple_size<Tuple>::value)
+      >
+  struct ElementPrinter {
+      static void print( const Tuple& tuple, std::ostream& os )
+      {
+          os << ( N ? ", " : " " )
+             << Catch::toString(std::get<N>(tuple));
+          ElementPrinter<Tuple,N+1>::print(tuple,os);
+      }
+  };
+
+  template<
+      typename Tuple,
+      std::size_t N
+      >
+  struct ElementPrinter<Tuple,N,false> {
+      static void print( const Tuple&, std::ostream& ) {}
+  };
+
+}
+
+template<typename ...Types>
+struct StringMaker<std::tuple<Types...>> {
+
+    static std::string convert( const std::tuple<Types...>& tuple )
+    {
+        std::ostringstream os;
+        os << '{';
+        TupleDetail::ElementPrinter<std::tuple<Types...>>::print( tuple, os );
+        os << " }";
+        return os.str();
+    }
+};
+#endif
+
 namespace Detail {
     template<typename T>
     std::string makeString( T const& value ) {