Add wxText{Input,Output}Stream::Get{Input,Output}Stream() methods.

These methods simply return the underlying low-level stream.

See #10807.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67286 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/txtstrm.h

@@ -45,6 +45,8 @@ public:
 #endif
     ~wxTextInputStream();
 
+    const wxInputStream& GetInputStream() const { return m_input; }
+
     wxUint32 Read32(int base = 10); // base may be between 2 and 36, inclusive, or the special 0 (= C format)
     wxUint16 Read16(int base = 10);
     wxUint8  Read8(int base = 10);
@@ -116,6 +118,8 @@ public:
 #endif
     virtual ~wxTextOutputStream();
 
+    const wxOutputStream& GetOutputStream() const { return m_output; }
+
     void SetMode( wxEOL mode = wxEOL_NATIVE );
     wxEOL GetMode() { return m_mode; }