Re: opUnary with ++ and -- on a struct that has a dynamic array

[aliak via Digitalmars-d-learn]

On Monday, 12 February 2018 at 06:16:21 UTC, rumbu wrote:

writeln(a++) translates to:

A copy = a;
a.opUnary!"++";
writeln(copy);

copy.a[] and a.a[] are the same reference, you increment a.a[0]/copy.a[0] in opUnary

to make this work you will need a postblit constructor:

struct A
{
   ....
   this(this)
   {
     a = a.dup; //make a copy a;
   }
}

In fact, you'll find exactly the same scenario in docs: https://dlang.org/spec/struct.html#struct-postblit

Ah! Awesome. Yes that works, thank you!

Cheers