fn require(comptime TRAIT: var) void {
    const fn_names_to_check = @typeInfo(TRAIT).Struct;
}

const default = struct {
    fn testing() Wrapper() { return Wrapper; }
};

fn Wrapper() type {
    comptime { require(default); }

    return struct {};
}

pub fn main() void {

    var crash = default.testing();
}