This spreads out transitively to many places and requires that
we use `check_call!` instead of `check_one_call` in a number of
places.
(cherry picked from commit 6bc31dcf206518a7be7f0ac6e773d5dfe25531ea)
> I couldn't figure out a way to use () for the function call, but I didn't try that hard.
I (Robert) have also given it a shot, briefly, unsuccessfully.
While I was critical of over-engineering this, it turns out that
when we start to use `mut`, a macro is much more practical, because
it doesn't create a new scope where we need a copy of a mutable
reference, which of course is not allowed.
(cherry picked from commit a2acc93d13991da4b14a99065acd589477334d07)
The mutation-based methods had some pitfalls, and we don't really
need them.
We could re-add them if we need to.
(cherry picked from commit ca92b8491d87cebf54dd2468599168fc7a16c07f)
This makes it easier to stick to a regular pattern and not forget
to check the context afterwards.
(cherry picked from commit 966ef3769a23075f5d660a48cf5a7307df925dbf)
This is slightly easier to use than the previous pattern that was
always followed up by the same conversions.
(cherry picked from commit 756c080730cd4fa81d4c0e3a99688cbe8debe57f)
