zroff https://blog.hatena.ne.jp/zroff/ wをしても一人 https://zroff.hatenadiary.org/ offsetofマクロの存在を知る。 #include <stdio.h> #include <stddef.h> typedef enum { OP_CHAR, OP_CONCAT, OP_ALTER, OP_CLOSURE, OP_NULL } Op_t; typedef struct Tree { Op_t Op; union { char c; struct { struct Tree *_left; struct Tree *_right; }X; }U; }Tree_t; int main(void) { Tree_t t; printf("t=%d,op=%d,o_op=%d,U… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fzroff.hatenadiary.org%2Fentry%2F20090108%2F1231448281" title="プログラミング C言語　復習　構造体　共用体 offsetof - wをしても一人 " class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> Hatena Blog https://hatena.blog 2009-01-08 05:58:01 rich https://zroff.hatenadiary.org/entry/20090108/1231448281 1.0 100%