'struct_declarator   : declarator COLON constant_expression
| COLON constant_expression'

def p_struct_declarator_2(self, p):

    if (len(p) > 3):
        p[0] = {'decl': p[1], 'bitsize': p[3]}
    else:
        p[0] = {'decl': c_ast.TypeDecl(None, None, None), 'bitsize': p[2]}
