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1要素分は確保されるのかねえ

$ cat main.c
#include <stdlib.h>
#include <stdio.h>

int main(void)
{
char empty[] = {};
char single[] = { 0 };
printf("single:\t%p\nempty:\t%p\n", single, empty);
return 0;
}
$ gcc -Wall main.c && ./a.out
single: 0x16fb6b4ba
empty: 0x16fb6b4bb

ひとさまの配列にちょっかいは出せる #やめとき

$ cat main.c
#include <stdlib.h>
#include <stdio.h>

int main(void)
{
char empty[] = {};
char single[] = { 0 };
printf("single[0]: %d\n", single[0]);
empty[-1] = 42;
printf("single[0]: %d\n", single[0]);
return 0;
}
$ gcc -Wall main.c && ./a.out
main.c:9:3: warning: array index -1 is before the beginning of the array [-Warray-bounds]
empty[-1] = 42;
^ ~~
main.c:6:3: note: array 'empty' declared here
char empty[] = {};
^
1 warning generated.
single[0]: 0
single[0]: 42

空の配列なのに変化する要素w (ビールそろそろ冷えたかな ((まだでしょ

$ cat main.c
#include <stdlib.h>
#include <stdio.h>

int main(void)
{
char empty[] = {};
char single[] = { 0 };
printf("empty[0]: %d\n", empty[0]);
single[1] = 42;
printf("empty[0]: %d\n", empty[0]);
return 0;
}
$ gcc -Wall main.c && ./a.out
main.c:9:3: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
single[1] = 42;
^ ~
main.c:7:3: note: array 'single' declared here
char single[] = { 0 };
^
1 warning generated.
empty[0]: 4
empty[0]: 42