Convert array to a tuple

Question

I have a function that accepts a struct

fn foo(args: anytype) void {
    const ArgsType = TypeOf(args);
    const args_type_info = typeInfo(ArgsType);

    switch (args_type_info) {
        .Struct => { // do work
        },
        else => @compileError("tuple or struct expected"),
}

I want to pass array elements as a tuple to this function, but the only way I know of is to write all elements manually

const SIZE = 3;
var array = [_]u8{0} ** SIZE;
foo(.{ array[0], array[1], array[2] });

Is there a way to do this automatically in comptime so that if I change SIZE to 100 I don't have to type all elements by hands?

I know I can extend switch to take .Array but I'm wondering if I can do it with just .Struct

Why do you want to use `.Struct` if your goal is to pass in an array? — mkrieger1, May 25 '23 at 19:09
@mkrieger1 No particular reason. Just wondering if it's possible — KindFrog, May 25 '23 at 19:20
FYI: Looks like 0.11 will have [type coercion of tuples to arrays](https://ziglang.org/documentation/master/#Type-Coercion-Tuples-to-Arrays). — sigod, May 26 '23 at 10:12

score 2 · Answer 1 · answered Jun 04 '23 at 22:57

std.meta.Tuple(slice) could treat this, however, the latest compiler cannot do this because of a bug.

https://github.com/ziglang/zig/issues/15822

Moreover, comptime range slice¹ generation is also difficult because of another bug.

https://github.com/ziglang/zig/issues/6936

₁: see https://github.com/nektro/zig-range/blob/master/src/lib.zig

Convert array to a tuple

1 Answers1