Old dog, old C struct tricks

Mon, 14 Jul 2025 20:00:00 +0800

Look at this code snippet and tell me with a straight face you didn’t think it was a memory leak at first either..

A while ago I worked on some code which contained a container that looked like this:

struct S
{
 size_t sz;
 int data[1];

 void Set(size_t _sz, int *_data){
 sz = _sz;
 memcpy(data, _data, sizeof(int)*sz);
 }
}

If you’re a modern programmer like me, you might be looking at this and thinking: there’s no way this isn’t a flagrant memory violation in almost every case. Right? Well, it turns out this is something them old boys before C99 used to do.

Struct on icyveins7's blog

Old dog, old C struct tricks