make Cython understand 'size_t' as a native C type

[dalcinl]

 http://codespeak.net/pipermail/cython-dev/2009-February/003670.html

[scoder]

Copying this here from the mailing list:

	static INLINE size_t __pyx_PyInt_AsSize_t(PyObject* b) {
 		 unsigned PY_LONG_LONG val =
				 __pyx_PyInt_AsUnsignedLongLong(b);
 		 if (unlikely(val == (unsigned PY_LONG_LONG)-1 &&
				 PyErr_Occurred())) {
 		       return (size_t)-1;

The (size_t)-1 definitely looks funny. I noticed that (unsigned PY_LONG_LONG)-1 is also used in __pyx_PyInt_AsUnsignedLongLong(), so I just hope it does the right thing.

 		  } else if (unlikely((unsigned PY_LONG_LONG)(size_t)val
							 != val)) {
 		       PyErr_SetString(PyExc_OverflowError, "value too
					 large to convert to size_t");

This should return an error value, so it lacks a return (size_t)-1.

 		  }
 		  return val;
	}

It would be great if we had tests for the error cases. It's not obvious that they work as expected. The same applies to the "unsigned long long" conversion, IMHO.