chickadee » sdl2 » struct-null?

struct-null? recordprocedure

Returns #t if the given record is a null struct record, i.e. it has a pointer to memory address 0. This procedure can be used with any struct record type provided by this library, or related libraries such as sdl2-ttf.

A struct record will be null after you manually free its memory, e.g. using free-surface!. Most procedures, including field getters and setters, will signal an error if you pass a null struct record. So, you can use this procedure to check whether it is safe to use the record.

It is possible for a C function to return a null struct record. But, if a function binding in this library returns a null struct record, that is a bug and should be reported. Function bindings in this library are supposed to return #f instead of a null struct record.