Comments on: Helping newbies is fun

By: Tollef Fog Heen

Tollef Fog Heen — Wed, 30 Nov -0001 00:00:00 +0000

For an example of 3, look at functions such as realloc.

By: Anonymous

Anonymous — Wed, 30 Nov -0001 00:00:00 +0000

> I’ve never seen any function acting like that, to be honest.

The GList and GSList functions work that way — you pass in the list head, and they return to you the potentially changed list head.

By: Christian Neumair

Christian Neumair — Wed, 30 Nov -0001 00:00:00 +0000

Tollef: You’re totally right, thanks for pointing that out.

anonymous: No, they don’t modify the location of the passed-in pointer, but the members of the struct the passed-in pointer points to.

By: Mathias Hasselmann

Mathias Hasselmann — Wed, 30 Nov -0001 00:00:00 +0000

Chris, g_list_append modifies the pointer in the very special case, that you pass an empty list: You pass in the NULL pointer and you get back the pointer on a newly allocated list . g_list_prepend also returns another pointer than passed in.

By: Christian Neumair

Christian Neumair — Wed, 30 Nov -0001 00:00:00 +0000

Mathias: g_list_append/prepend seems to malloc a new list as return value, no matter whether the argument is NULL or not. For the caller, this is completely transparent (because of call-by-value), but technically this is 4, with the const modifier removed. Just take a peek at the GList source code.