const print = @import("std").debug.print;
const SomeStruct = struct { inner: ?usize = null };

pub fn Box(comptime T: type) type {
    return struct {
        inner: ?*T,
        fn drop(self: *Box(T)) void {
            self.inner.?.* = SomeStruct{ .inner = 1000 };
        }
    };
}

pub fn main() void {
    var s = SomeStruct{};
    var box = Box(SomeStruct){ .inner = &s };
    s.inner = 100;

    print("{any}\n", .{box.inner == &s});
    print("{any}\n", .{box.inner.?.inner});
    box.drop();
    print("{any}\n", .{box.inner == &s});
    print("{any}\n", .{box.inner});
    print("{any}\n", .{s});
}