scope(failure) - Programming in D, doesn't catch throw. When should scope (failure) be used?

[kdevel]

On Wednesday, 26 November 2025 at 18:42:16 UTC, Brother Bill 
wrote:
> I would expect if that is so, then the program shouldn't crash.
>
> If this is correct, when should scope(exit), scope(success) and 
> scope(error) be used, if ever?

Though it is not correct the scope exit clauses should be used 
for cleanup. Not for anything that may throw itself.


```d
import std;

enum Op { pass, fail }

int worker (Op op)
{
    scope (exit)
       writeln ("worker exit: op = ", op);

    writeln ("worker entry: op = ", op);

    final switch (op) {
       case Op.pass:
          return 0;
       case Op.fail:
          throw new Exception ("failing...");
    }
}

int doit (string [] args)
{
    scope (exit)    writeln ("scope exit");
    scope (success) writeln ("scope success");
    scope (failure) writeln ("scope failure");

    enforce (args.length == 2, format ("usage: %s (pass|fail)", 
args [0]));

    auto op = args [1].to!Op;
    return worker (op);
}

int main (string [] args)
{
    try return doit (args);
    catch (Exception e) stderr.writeln (e.msg);
    return 1;
}
```