On Wednesday, 19 September 2018 at 21:16:00 UTC, Steven
Schveighoffer wrote:
Given dip1008, we now can throw exceptions inside @nogc code!
This is really cool, and helps make code that uses exceptions
or errors @nogc. Except...
The mechanism to report what actually went wrong for an
exception is a string passed to the exception during
*construction*. Given that you likely want to make such an
exception inside a @nogc function, you are limited to passing a
compile-time-generated string (either a literal or one
generated via CTFE).
<snip>
I expressed my concern for DIP1008 and the `msg` field when it
was first announced. I think the fix is easy and a one line
change to dmd. I also expressed this on that thread but was
apparently ignored. What's the fix? Have the compiler insert a
call to the exception's destructor at the end of the `catch(scope
Exception)` block. That's it. The `msg` field is just a slice,
point it to RAII managed memory and you're good to go.
Give me deterministic destruction of exceptions caught by scope
when using dip1008 and I'll give you @nogc exception throwing
immediately. I've even already written the code!
