Should a file header be a class or a struct?

I'm parsing a file format with a header. (Note: I don't write any files, I only read and parse)

Because it won't be changed, its header can be passed by value. So I would guess a struct would be the best choice but I'm not sure because I almost never use them.

Is there any reason why I should (not) make it a class or a struct?

Edit: It's hard to provide an example at the moment. You can compare it to any basic file header. It includes the si开发者_Python百科gnature ('magic number'), the version and the 'sub-type'.

The "won't be changed" part is an indicator for immutable, not for value-type.

You probably want a class, but it's impossible to be sure without an example.

If you are going to use Serialization then I suggest class.