scope(exit) considered harmful

[Walter Bright]

Justin Johansson wrote:
> Long ago in the days before D, I was used to commenting out code with one of
> two idioms:
> 
> #if false
> .. this code is not compiled
> #endif
> 
> or
> 
> if (false) {
> .. this code is compiled but not executed
> }
> 
> and to turn stuff back on again:
> 
> #if true
> .. this code is back on now
> #endif
> 
> or
> 
> if (true) {
> .. this code is back on now too
> }
> 
> but in the D world beware the Ides of Scopes because if your curly
> brace block with the true/false conditional contains a scope(exit)
> you will get explainable but unexpected behaviour if this code
> is enabled inside an if(true) block.
> 
> Gotcha.

This is incorrect. Given:

     if (false)
     {
           scope(exit) writeln("hello world!");
     }

The writeln will never execute.