#ifndef CONVERT_CAREFULLY
# define CONVERT_CAREFULLY(newty, expty, obj) \
(!sizeof(*(expty *)0 = (obj)) + (/*unconst*/ newty)(obj))
#ifndef CONVERT_CAREFULLY
# define CONVERT_CAREFULLY(newty, expty, obj) \
(!sizeof(*(expty *)0 = (obj)) + (/*unconst*/ newty)(obj))