1const builtin = @import("builtin");
 2const expect = @import("std").testing.expect;
 3
 4const Foo = struct {
 5    a: u64 = 10,
 6
 7    fn one(self: Foo) u64 {
 8        return self.a + 1;
 9    }
10
11    const two = __two;
12
13    fn __two(self: Foo) u64 {
14        return self.a + 2;
15    }
16
17    const three = __three;
18
19    const four = custom(Foo, 4);
20};
21
22fn __three(self: Foo) u64 {
23    return self.a + 3;
24}
25
26fn custom(comptime T: type, comptime num: u64) fn (T) u64 {
27    return struct {
28        fn function(self: T) u64 {
29            return self.a + num;
30        }
31    }.function;
32}
33
34test "fn delegation" {
35    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
36    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
37
38    const foo = Foo{};
39    try expect(foo.one() == 11);
40    try expect(foo.two() == 12);
41    try expect(foo.three() == 13);
42    try expect(foo.four() == 14);
43}