Function to byte-swap all members of a struct in zig using reflection

byte_swap_all_members.zig

const assert = std.debug.assert;
// uses reflection to byte-swap all members of a packed struct
// layout is preserved
fn byte_swap_all_members(comptime T: type, struct_pointer: *T) void {
    comptime assert(@typeInfo(T).Struct.layout != .Auto);
    comptime assert(@mod(@bitSizeOf(T), 8) == 0);
    var raw_bytes = @ptrCast([*]u8, std.mem.asBytes(struct_pointer));
    comptime var start_index: u32 = 0;
    inline for (std.meta.fields(T)) |field| {
        const length = @bitSizeOf(field.field_type) / 8;
        const slice = raw_bytes[start_index .. start_index + length];
        const value_ptr = std.mem.bytesAsValue(field.field_type, slice);
        value_ptr.* = @byteSwap(field.field_type, value_ptr.*);
        start_index += length;
    }
}