[libcxx-commits] [libcxx] [libc++] fix minor performance issue in `basic_string<C>::append()` (PR #210078)

[Pavel Novikov via libcxx-commits]

toughengineer wrote:

Of course as soon as I answered, I came up with several "realistic" examples:
- iterators into some kind of file with such a format that it does not allow to have random access iterators,
- iterators into a compressed stream,
- iterators into a range with arbitrary processing (e.g. filtering, transformation, generation) can be arbitrarily expensive to iterate over (this is actually a generalization of the previous two).

@philnik777, please let me know if you are still not convinced.

https://github.com/llvm/llvm-project/pull/210078