SocketErrorException is now a std::system_error: code() carries the errno
under std::generic_category(), or getaddrinfo's result under the new
ResolverCategory(), whose message() is gai_strerror's text; `phase` says
which step failed (resolve, open, connect, send, receive). It is still a
std::runtime_error with the message ClientTCP always threw, the code's
text after it, so existing handlers keep working.
Before, the exception carried a `kind` and an int, and a caller that had
to print the cause its own way still had to match the message prefix to
learn where the failure happened. The standard type ends both: the
category knows how to print the number, and the phase is a field. A
caller writes "[Errno {}] {}" from code().value() and code().message(),
or compares code() with std::errc::connection_refused.
Breaking: SocketErrorException's `kind` and `code` members are gone;
read code().category() and code().value().
- ClientTCP resolves with AF_UNSPEC and tries every address the name
resolves to, in getaddrinfo's order, the way Python's
socket.create_connection does. It used to ask for AF_INET only and keep
the first answer, so `localhost` could not reach a server listening on
::1 alone, which is what a dev server on a recent Node does. The connect
timeout bounds each address on its own; when none connects, what the
last one failed with is thrown.
- A failed resolve, socket() or connect throws SocketErrorException: the
std::runtime_error it always was, with the same message, plus the errno
(SocketErrorKind::System) or the getaddrinfo code
(SocketErrorKind::Resolver). A caller that reports the cause in its own
words, such as a Python-style "[Errno 111] Connection refused", no
longer has to parse it back out of the text.
- The move constructor carries the resolved addresses along.
New: ShouldConnectDualStack, ShouldReportConnectErrors.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
