The following information pertains to an older version of the Elsa parser, but it might still be useful if you're having troubles with headers.

Elsa cannot yet parse all of C++. The main difficulty is heavily templatized code, such as is found in the Standard Template Library, which is part of the current version of the C++ Standard Library. In practice, this means that Elsa can only parse code that does not use STL, and when it includes library headers, uses the older

  #include <iostream.h>
form, instead of the newer
  #include <iostream>
form. We are working on support for the new-style headers, but it may be some time before that support is reliable. (See also Marshal Cline's FAQ on new-style headers.)

Note: In newer versions of gcc, the old-style headers simply #include the new-style headers. So, try to preprocess the code using an older version of gcc (and hence the older version of the associated headers). I've had good success with gcc-2.95.3.