"Christopher Kohlhoff" <chris@kohlhoff.com> wrote in message news:20060724133406.3655.qmail@web32610.mail.mud.yahoo.com...
Hi Beman
Beman Dawes <bdawes@acm.org> wrote:
* Class error_code now supports additional categories of errors, such as those that may bubble up from asio. I'll be watching for for a response from Chris to make sure this meets asio's needs.
Looks good! I have just uploaded a version of asio that has been modified to use error_code and system_error where appropriate. It's in the vault, in the System directory.
Just a few minor things:
- the system_error::what() function is defined in system_error.hpp without being inline, causing multiple definition linker errors.
Nuts! That's about the millionth time I've made that mistake. Will fix.
- I'm not sure about the category names errno_ec and native_ec, since I keep reading the "ec" as error_code. I don't have any good suggestions, except perhaps more verbose names likes errno_category and native_error_category.
I started out with errno_category and native_error_category (or something similar), but found them overly verbose in some real code I converted.
- The Jamfile is doing something strange when I try to link the boost_system library from the asio unit test Jamfile, but it works fine when used from non-test Jamfiles.
Hum.... Not sure what to make of that. What error are you getting?
- The boost::identifier iostream operators aren't always working correctly with VC8. For example, try compiling the asio serialization example, which gives errors saying operator>> is ambiguous.
They aren't that critical, so could be removed if necessary. Perhaps some enable_if expert could take a look and see how to make them less likely to cause ambiguities.
- error_code::new_category probably needs to be made thread-safe, or the limitations on when it can be called should be documented.
Do we have a portable way to make it thread safe?
- You might want to add special handling when converting the success errno (i.e. 0) to a string on POSIX. The strerror function doesn't give you a string for it, so you end up with "EINVAL", which is a bit surprising.
To say the least. I'll add some special handling. Good catch!
Converting asio to use this stuff was a non-trivial exercise, so I can confidently say I now have extensive experience using these classes ;) I'm happy with the interface -- it's clean and easy to use, particularly when it comes to defining new error categories.
Good, it makes me really happy to hear you say that:-) I was worried that I might be so deep in the forest I could only see the trees. Thanks for the report, --Beman