Split out Catch::cout/cerr/clog into their own file

src/catch2/internal/catch_stdstreams.cpp

@@ -0,0 +1,24 @@
+
+//              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/internal/catch_stdstreams.hpp>
+
+#include <catch2/catch_user_config.hpp>
+
+#include <iostream>
+
+namespace Catch {
+
+// If you #define this you must implement these functions
+#if !defined( CATCH_CONFIG_NOSTDOUT )
+    std::ostream& cout() { return std::cout; }
+    std::ostream& cerr() { return std::cerr; }
+    std::ostream& clog() { return std::clog; }
+#endif
+
+} // namespace Catch