(((type *)((ap) += __va_sizeof__(type)))[-1])请问[-1]的作用,谢谢
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(((type *)((ap) += __va_sizeof__(type)))[-1])请问[-1]的作用,谢谢
本帖最后由 mp699 于 2010-8-25 17:29 编辑
使用CW5.0,在看内部函数算字节时碰到
#define va_arg(ap, type) (((type *)((ap) += __va_sizeof__(type)))[-1])
请问[-1]在里面的作用???谢谢 |
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应该 是 一个最大数,比如16位的单片机 就是 65535 ,8位的就是 255 |
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