A feature request regarding redirection to variables

[Luke Tidd]

A very common thing I need to do when writing bash is to collect both
the stdout and stderr of a command. This can be done relatively
reasonably with files but it would be very attractive to be able to
redirect these directly to a variable some how.

cmd >@stdout 2>@stderr
exit_code=$?

where "stdout" and "stderr" here are variables.
This or equivalent would be very nice. currently I find myself reusing
this pattern over and over:

err_file="$(mktemp)"
var_stdout="$(cmd 2>"$err_file)"
exit_code=$?
var_stderr="$(<"$err_file")"
rm "$err_file"

and it just doesn't have the same ring to it! Is there a snowballs
chance? Thanks for your time!