Re: union/toString: crash/segfault: What's happening here?

[ag0aep6g via Digitalmars-d-learn]

On 01/12/2018 02:45 AM, Nicholas Wilson wrote:
because you don't initialise `s` in
   string toString ()
   {
      string s;
      return s;
   }

so it defaults to `string s = null;` thus giving a segfault.

try `string s = "";` instead.

A null string is a perfectly fine empty string. Printing it does not 
lead to a segfault. And the thrown error is not a segfault.

Actually, the problem seems to be that s is not default initialized. 
It's garbage. And garbage usually isn't a proper string, so writeln 
fails. Looks like a compiler bug.