1const Foo = struct {};
 2fn doSomethingWithFoo(foo: *Foo) void {
 3    _ = foo;
 4}
 5
 6fn doAThing(optional_foo: ?*Foo) void {
 7    // do some stuff
 8
 9    if (optional_foo) |foo| {
10        doSomethingWithFoo(foo);
11    }
12
13    // do some stuff
14}
15
16// syntax