Unable to evaluate comptime expression, operation is runtime due to this operand. However, it is entirely compile time.

[AnneKitsune]

Zig Version

0.12.0

Steps to Reproduce and Observed Behavior

Code:

const std = @import("std");

const things = .{
    a // Compiles fine if I comment this, but not if I uncomment
} ++ gen(b);

pub fn main() !void {
    _ = things;
}

pub fn a() void {}
pub fn b(u: u32) void {_ = u;}

fn gen(comptime func: anytype) struct{@TypeOf(func)} {
    return .{
        func,
    };
}

output:

anne@umaru:/tmp/a/ > zig build run
run
└─ run a
   └─ zig build-exe a Debug native 1 errors
src/main.zig:5:3: error: unable to evaluate comptime expression
} ++ gen(b);
  ^~~~~~~~~
src/main.zig:5:9: note: operation is runtime due to this operand
} ++ gen(b);
     ~~~^~~
referenced by:
    main: src/main.zig:8:9
    callMain: /nix/store/ymq0w17q7vy4xf2phd74pqhsyfdmam3s-zig-0.12.0/lib/zig/std/start.zig:511:32
    remaining reference traces hidden; use '-freference-trace' to see all reference traces

Expected Behavior

Code compiling correctly.

[Pyrolistical]

I think you need a comptime infront of gen(b)