Add IStream::isStdOut

tests/SelfTest/IntrospectiveTests/Stream.tests.cpp

@@ -0,0 +1,19 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE_1_0.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/catch_test_macros.hpp>
+
+#include <catch2/internal/catch_stream.hpp>
+
+TEST_CASE( "Cout stream properly declares it writes to stdout", "[streams]" ) {
+    REQUIRE( Catch::makeStream( "-" )->isStdout() );
+}
+
+TEST_CASE( "Empty stream name opens cout stream", "[streams]" ) {
+    REQUIRE( Catch::makeStream( "" )->isStdout() );
+}