needing QList|QVector constLast() or clast()

It's nice that last() has an overload returning a const item but that's not enough.

Found hundreds of cases of detaching temporary containers in Qt and KDE.

For example:
if (foo.getList().first() == bar)

first() is easy to replace with at(0).

but last() is difficult to replace without:
1) writing boiler-plate code / increasing verbosity

2) loosing semantics/readability.

3) Assigning the temporary into a const list first. Which I tried in https://codereview.qt-project.org/#/c/112029 but resulted in bug-prone code, due to the non-trivial nature of the existing code

constFirst() would be welcome too, it has stronger semantics than at(0)