Hi,

In this simple example, the destructor for the struct is invoked four more times than expected:

----
import std.stdio;

struct Person {
  string name;
  int age;

  ~this() {
    writefln("%s is gone (0x%x)", name, &this);
  }
}

int main(string[] args) {
  Person* p = new Person;

  writefln ("Created person (0x%x)", p);
  p.name = "Peter";
  p.age = 23;

  writeln("Person:", *p); // Comment this line and try

  return 0;
}
----

Output:

Created person (0x7f85ee997000)
Person:Person("Peter", 23)Peter is gone (0x7ffd916c1560)
Peter is gone (0x7ffd916c15c0)

Peter is gone (0x7ffd916c1640)
Peter is gone (0x7ffd916c16f0)
Peter is gone (0x7f85ee997000)
-----

If I comment the line "writeln("Person:", *p);" then the destructor is invoked only one time as expected.

Why is it?

Because you passed it by value to writeln, which goes on to pass it to many other functions.

On Tuesday, 15 January 2019 at 10:49:17 UTC, rikki cattermole wrote:
> Because you passed it by value to writeln, which goes on to pass it to many other functions.

Thanks Rikki!

I was thinking about something like that.
Antonio