Problem:
- There is no way to signal that a copy should proceed, selecting
elements by a predicate until some condition is met. This is useful
for patterns along the lines of "copy selected elements until there
are n total elements in the output".
Solution:
- Introduce `copy_if_while()` and `copy_if_until()`.
Problem:
- There is no documentation for the existing functions. This will make
it harder for users to consume these functions, espcially as new
variants are added.
Solution:
- Add documentation.
Problem:
- There is no documentation for the existing functions. This will make
it harder for users to consume these functions, especially as new
variants are added.
Solution:
- Add documentation.
