Yesterday I got bitten by the wxWidgets (again). I tryed to get a C string from a wxString using the wxString::mb_str method.
Before continuing reading, read the documentation. What would you expect when you call the method?
My assumption was that if I call the
const char * version, it will return the address of some internal buffer, so I can use it as long the particular object is alive.
So I tried this:
wxString bar = wxT("BAR"); const char *pStr = bar.mb_str();
But not worked. I even reported a bug: #14633 (wxString::mb_str returns empty string or garbage on 64 bit Ubuntu.) – wxWidgets
After their response I found out only the
wxCharBuffer version exists, which can be converted implicitly to
So the returned object is only a temporary. Which is destroyed immediately after the call, so pStr will point to an invalid location immediately.
The solution: immediately copy its contents to a buffer:
wxString bar = wxT("BAR"); const char cstr; strncpy(cstr, bar.mb_str(), 1000);
This will work. But the documentation says nothing about this. Only their wiki: Converting everything to and from wxString. By the way what is a "temporary pointer"? I only know about temporary objects...