This function returns whether the given struct is an "instance of" the given constructor. You can use this function to check if the constructor used to create your struct was the same one as you supplied in the second argument, or if it's a child constructor of your given constructor.
This means that if your struct was created from constructor B, and constructor B is a child of constructor A, calling is_instanceof(struct_of_B, A) will return true.
This function works by checking the Static Chain of your given struct to see if your given constructor is included anywhere in that chain. See: Static Struct
NOTE If you use static_set to replace the static chain of a struct, it will modify the behaviour of this function on that struct, as it checks the static chain to determine inheritance. Using static_set is not recommended aside from deserialisation cases where an anonymous struct is loaded back as part of a hierarchy.
is_instanceof(struct, constructor_name);
| Argument | Type | Description |
|---|---|---|
| struct | Struct | The struct to check (the "instance") |
| constructor_name | Function | The constructor to check (is the struct an instance of this constructor?) |
function item() constructor {}
function potion() : item() constructor {}
function enemy() constructor {}
var _potion = new potion();
show_debug_message(is_instanceof(_potion, potion)); // true (1)
show_debug_message(is_instanceof(_potion, item)); // true (1)
show_debug_message(is_instanceof(_potion, enemy)); // false (0)
The above code shows three constructors: item, potion which is a child of item, and enemy, which is a separate constructor.
It creates a struct from the potion constructor. Using is_instanceof(), we can check that the new struct:
This way you can check whether a struct "is" something, as a potion is an item, so it returns true for both constructors. However if wouldn't be true the other way around: an item is not a potion.