Fix issue 18946: assert message can throw hijacking the assert failure

[thewilsonator]

I presume the protocol is to deprecate this first.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	18946	major	assert message can throw hijacking the assert failure.

Testing this PR locally

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[Geod24]

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[Geod24]

I am not sure the linked issue is valid. In the end, your exception happens last, and that's what gets reported. If the function was to assert, that would also be reported, wouldn't it ?

[thewilsonator]

Instead of throwingFunc replace that with a call to format or the like, which one might reasonably expect to catch a ConvException from some higher call chain call...

[Geod24]

@thewilsonator : Exactly. But forcing people to put nothrow on their string-formatting functions is quite restrictive IMO.

[thewilsonator]

Hmm, perhaps this is not the correct way to fix this. It would be better to wrap the message evaluation in a try catch.

[Geod24]

Yeah, that would be much better

[Geod24]

If you don't mind, I'm going to close this for the time being since this approach won't work.
This way it won't get scheduled into the CI queue.
Feel free to reopen when you implement the different approach.