'Modified length specifiers: mapping between length modifiers and conversion specifiers. This generates all the
possibilities, i.e. hhd, etc.'

@property
def _mod_spec(self):

    mod_spec = {}
    for (mod, sizes) in self.int_len_mod.iteritems():
        for conv in self.int_sign['signed']:
            mod_spec[(mod + conv)] = sizes[0]
        for conv in self.int_sign['unsigned']:
            mod_spec[(mod + conv)] = sizes[1]
    return mod_spec
