On Tue, 25 Apr 2023 at 13:13, Jonny Grant wrote: > > Hello > > https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > > I wondered 'this_length' refers to in that example, it doesn't compile.
It's not supposed to be a complete program. > > <source>: In function 'main': > <source>:13:34: error: 'this_length' undeclared (first use in this function) > 13 | malloc (sizeof (struct line) + this_length); > | ^~~~~~~~~~~ > > > https://godbolt.org/z/PWEcWsrKv > > I probably the size of the struct? So that would be 4 bytes for me, as it is > just the int. That doesn't seem very useful. Maybe I am missing something. Yes, you are. Look at how it's used: malloc is called to allocate sizeof(struct line) + this_length bytes. Why would it be the size of the struct? It's the number of bytes that the zero-length contents array can hold.
