Re: Proper way to protect (lock) a struct field after initialization ??

[james.p.leblanc via Digitalmars-d-learn]

On Sunday, 8 August 2021 at 10:40:51 UTC, Ali Çehreli wrote:

I understand your question differently from jfondren. You may 
be looking for a 'const' (or 'immutable') member:

struct S {
  const int i;

  this(int i) {
    // This will work because "first assignment is 
initialization"
    this.i = i;
  }
}

void main() {
  auto s = S(42);

  // This won't work
  s.i = 43;

  // This won't work either
  s = S(44);
}

Ali

Hello Again Ali,

Excellent!  I had tried (an erroneous) variant of this idea 
earlier ... but
also failed with my attempt.

I am appreciating very much the example you have provided.  I 
will try
this approach as well for the problem I am working on.  (Some 
details on
my path forward remain unclear ...)

Best Regards,
James