What's the point of a `readonly struct` if the types aren't implicitly made `readonly`?

What's the difference between a struct with ALL readonly fields, and a readonly struct, which requires you to explicitly state all fields as readonly?
This just seems like an extra KW for no reason, if it's not implicitly making things readonly.

Thanks!
Cheers!

Comments

[Calin Baenen]

Why doesn't it just implicitly make everything readonly for me, then?
Surely it would be thought through that having a bunch of readonlys, or {get;}s in a struct that has already been declared readonly is kind of redundant, and (in my opinion) ugly.

[Miles Watson]

It makes it clearer to other programmers that they shouldn’t try and add mutable fields. It also has the added benefit of allowing better compiler optimisation. I would recommend using a record as opposed to a read only struct in most situations.

docs.microsoft.com/en-us/dotnet/st...

[Calin Baenen]

Huh? But isn't readonly like final (from Java)???
I think I'm confused.