avoid potential null dereferences

[dornbirndevelops]

with some warnings enabled, gcc 13 and above detect a potential null pointer dereference in the typed_value::notify member function.

[vprus]

Thanks for the PR.

Can you tell why value might end up null? It seems like it's only possible due to user error and then it's better to crash than silently ignoring it?

[dornbirndevelops]

Hi @vprus, thank you for the quick response.

I created a minimum reproducible example of my problem in compiler explorer using boost 1.86.0.
https://godbolt.org/z/efP1WxoKT

I tried to stick with the original example from the docs to minimize the chance of user error.
https://www.boost.org/doc/libs/1_86_0/doc/html/program_options/tutorial.html