`free` for struct with C bindings.

[Jonathan]

I am using a C bindings library 
(https://code.dlang.org/packages/xcb-d).

I am following through a tutorial that was written for the C 
library directly and just making the minor changes to make it 
work with D.

I ran into a problem. The library ends up giving me a struct 
pointer.

```
xcb_generic_event_t*	event;
event = xcb_wait_for_event (connection);
free (event);
```

The problem is the `free` function.  It is not provided by the 
library but is part of the C standard library (in stdlib.h).

Do I need to call this function with my D code?  I tried using 
the `core.memory.GC.free` function from the D standard library 
and it compiled and ran but that does not necessarily mean there 
are not memory leaks (it also ran with the line entirely removed).

Do I need to call the `free` function with my D code because I 
need to free memory that was allocated in C code?