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Re: [SG16-Unicode] SG16 approval for LEWG to review std::filesystem::path_view

From: Lyberta <lyberta_at_[hidden]>
Date: Wed, 03 Jul 2019 19:40:00 +0000
JeanHeyd Meneide:
> Finally, I have one more... thing? It's not really a concern or a nit
> with the paper, just a bit of sadness: had we standardized a c_string_view
> of some form, we wouldn't need what will probably amount of "*Expects:
> *ptr[size]
> == 0 is true" on all the specifications on the constructors for the string
> view / charX + pointer overloads. I agree with the reasoning in the paper
> that there is rarely a case where users expect that to be the case, but
> it's not exactly impossible: I have received a lovely crop of bug reports
> from people seeing "std::string_view" overloads in my libraries and passing
> non-null-terminated strings into them, because that's what string_view
> promises. Whether or not your wording has an "expects" clause, it's not
> difficult or hard to imagine substring or other similar pointer + size
> manipulations to produce hell here.
> Then again, this is marked as the *path*_view type. Maybe that will
> be enough visual indication to the user they should think carefully and not
> just toss in random substrings. I certainly hope it is.

Since std::c_string_view would not own the string, how do you enforce
the null terminator because the user can mutate the buffer. Do you check
manually in every member function and assert?

Received on 2019-07-03 21:40:22