"{1,numb}" instead of {1,num} or {1,number}
If boost.format throws it may accidentally stop the program and both translator and programmer would give very hard times to understand what is going.
Okay, I can buy that in some circumstances, you want syntax errors to be silently ignored. This appears to be mostly because the allowable syntax can vary with the runtime locale; is that correct? (I've only skimmed the first few pages of the documentation so I should probably go through it more thoroughly. I was completely unfamiliar with localization until this review came up.)
Not, it is mostly because we don't want that translator would screw the program accidentally.
So by no means the formatting string should cause
an exception, it may cause invalid output that the translator would see and fix but not abort the entire program.
Based on your knowledge and experience in this domain, I take it at your word that swallowing syntax errors is the typical use case. But I'm skeptical that this use case is the only relevant one for all users all the time. You haven't given any argument against simply opening up the interface to allow the user to specify the error behavior, with the default being to swallow the error. To me, this wouldn't change the typical use case, and, on the implementation side, I wouldn't expect it to be technically challenging.
I'll think about it, may be it is good idea to add throw on syntax error behavior even thou it is really not desired.
I do appreciate you taking the time to bear with me and to explain to me in detail your rationale.
- Jeff
Best, Artyom