How to pass struct byref and readonly to a function in C#? -

is possible pass struct byref , readonly function? (just t const& in c++)

struct {     public int b; } void func1(ref a)  // want make `a` immutable {  } 

how that?

update

my biggest concern passing (1) immutable state (2) efficiently. second concern mutating state must simple , easy mutable object.

currently doing this. kind of boxing.

class immutablebox<t> t : struct, new() {     public readonly t state;     immutablebox(t state)     {         this.state = state;     } }  struct examplestatea {     public string somefield; }  void func1(immutablebox<examplestatea> passimmutablestatewithbox) { } 

by keeping instance of immutablebox<t>, can pass immutable object pointer copy, , it's still easy edit state because state mutable. gain chance optimize equality comparison pointer comparison.