copy and remove_all with error_code throws

[unravel-dev]

First of all - finally one working impl. Great job!

Describe the bug
copy and remove_all with error_code throws exceptions due to the error code not being propagated to the directory_iterator's constructor when iterating over the files.

        for (const directory_entry& x : directory_iterator(from)) {

    for (const directory_entry& de : directory_iterator(p)) {

shoud be

        for (const directory_entry& x : directory_iterator(from, ec)) {

    for (const directory_entry& de : directory_iterator(p, ec)) {

Expected behavior
These should not throw when using the error_code api

[gulrak]

Thank you, for the kind words, and for the bug report. Indeed I missed those, and it hides two other issues. More test code to write...

[gulrak]

Okay, I didn't run the tests on all my platforms yet (just fixed it from a macOS machine), but the fix is not complex, so I guess it will compile and work, and I will run tests on the other systems soon.
The next regular release v1.0.6 with the fix is scheduled for the upcomming weekend.

[gulrak]

Actually even that fix is not enough. After more digging, another problem is actually using the error_code variant of directory_iterator in a range-based for loop, as it calls operator++ and that is not exception-free. Working on a fix. Need to use an explicit loop for guaranteed exception safety.

[gulrak]

All tests look good.