Magic Methods
Magic methods are struct methods with a special name. These are not supposed to be called directly by the programmer but rather by the compiler.
Destructors
The destructor is called when an object goes out of scope. It is commonly used to clean up resources associated with the object. See Moving Values for info about moving objects.
use std.memory;
struct SmartPtr {
var ptr: addr;
func new(size: usize) -> SmartPtr {
return SmartPtr { ptr: memory.alloc(size) };
}
func __deinit__(self) {
memory.free(self.ptr);
}
}
func main() {
var ptr1 = SmartPtr.new(100);
var a = 10;
if a == 10 {
var ptr2 = SmartPtr.new(20);
# Destructor of 'ptr2' is called here
}
# Destructor of 'ptr1' is called here
}
Operator Overloading
Some operators can be overloaded for structs.
struct Vec2 {
var x: i32;
var y: i32;
func __add__(self, rhs: Vec2) -> Vec2 {
return Vec2 {
x: self.x + rhs.x,
y: self.y + rhs.y
};
}
func __sub__(self, rhs: Vec2) -> Vec2 {
return Vec2 {
x: self.x - rhs.x,
y: self.y - rhs.y
};
}
func __mul__(self, rhs: i32) -> Vec2 {
return Vec2 {
x: self.x * rhs
y: self.y * rhs
};
}
}
func main() {
var a = Vec2 { x: 10, y: 30 };
var b = Vec2 { x: 5, y: -10 };
var c = a + b;
println(c.x); # 15
println(c.y); # 20
var d = a - b;
println(d.x); # 5
println(d.y); # 40
var e = a * 3;
println(e.x); # 30
println(e.y); # 90
}
These are the operators that can currently be overloaded:
Operator |
Magic Method |
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