On the D Blog--Symphony of Destruction: Structs, Classes, and the GC

[Dukc]

On Thursday, 4 March 2021 at 13:54:48 UTC, Mike Parker wrote:
>
> The blog:
> https://dlang.org/blog/2021/03/04/symphony-of-destruction-structs-classes-and-the-gc-part-one/

"Some examples: attempting to index an associative array can 
trigger an attempt to allocate a RangeError if the key is not 
present; a failed assert will result in allocation of an 
AssertError; calling any function not annotated with @nogc means 
GC operations are always possible in the call stack. These and 
any such operations should be avoided in the destructors of 
GC-managed objects."

I don't understand this part. If an assert was failing, the 
program is going to terminate anyway, so 
InvalidMemoryOperationError is no problem. Well, it might 
obfuscate the underlying error if there is no stack trace, but 
banning `assert`ing in anything that could be called by a 
destructor sounds too drastic to me. Even the lowest level system 
code tends to contain asserts in D, at least in my codebase. If 
asserting is banned, destructors can do faily much nothing. I'd 
think it's much more practical to redefine the assert failure 
handler if InvalidMemoryOperationError due to a failed assert is 
a problem.