zig/test/cases/this.zig

const assert = @import("std").debug.assert;
const module = this;

struct Point(inline T: type) {
    const Self = this;
    x: T,
    y: T,

    fn addOne(self: &Self) {
        self.x += 1;
        self.y += 1;
    }
}

fn add(x: i32, y: i32) -> i32 {
    x + y
}

fn factorial(x: i32) -> i32 {
    const selfFn = this;
    if (x == 0) {
        1
    } else {
        x * selfFn(x - 1)
    }
}

fn thisReferToModuleCallPrivateFn() {
    @setFnTest(this, true);

    assert(module.add(1, 2) == 3);
}

fn thisReferToContainer() {
    @setFnTest(this, true);

    var pt = Point(i32) {
        .x = 12,
        .y = 34,
    };
    pt.addOne();
    assert(pt.x == 13);
    assert(pt.y == 35);
}

fn thisReferToFn() {
    @setFnTest(this, true);

    assert(factorial(5) == 120);
}