first phase of transition to unified Unicode build:

1. changed c_str() to return wxCStrData (implicitly convertible to wxChar*)
2. added template type-safe wrappers for vararg functions
3. added wxUniChar class representing single Unicode character
4. changed wxString::operator[] and wxString::iterator to return wxUniChar


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@44865 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/sstream.cpp

@@ -42,7 +42,7 @@ wxStringInputStream::wxStringInputStream(const wxString& s)
 #if wxUSE_UNICODE
     : m_str(s), m_buf(wxMBConvUTF8().cWX2MB(s).release()), m_len(strlen(m_buf))
 #else
-    : m_str(s), m_buf((char*)s.c_str()), m_len(s.length())
+    : m_str(s), m_buf((char*)(const char*)s.c_str()), m_len(s.length())
 #endif
 {
 #if wxUSE_UNICODE