rust-cpython: rename PyLeakedRef to PyLeaked
This series will make PyLeaked* behave more like a Python iterator, which
means mutation of the owner object will be allowed and the leaked reference
(i.e. the iterator) will be invalidated instead.
I'll add PyLeakedRef/PyLeakedRefMut structs which will represent a "borrowed"
state, and prevent the underlying value from being mutably borrowed while the
leaked reference is in use:
let shared = self.inner_shared(py);
let leaked = shared.leak_immutable();
{
let leaked_ref: PyLeakedRef<_> = leaked.borrow(py);
shared.borrow_mut(); // panics since the underlying value is borrowed
}
shared.borrow_mut(); // allowed
The relation between PyLeaked* structs is quite similar to RefCell/Ref/RefMut,
but the implementation can't be reused because the borrowing state will have
to be shared across objects having no lifetime relation.
PyLeaked isn't named as PyLeakedCell since it isn't actually a cell in that
leaked.borrow_mut() will require &mut self.
$ hg init a
$ cd a
$ touch empty1
$ hg add empty1
$ hg commit -m 'add empty1'
$ touch empty2
$ hg add empty2
$ hg commit -m 'add empty2'
$ hg up -C 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ touch empty3
$ hg add empty3
$ hg commit -m 'add empty3'
created new head
$ hg heads
changeset: 2:a1cb177e0d44
tag: tip
parent: 0:1e1d9c4e5b64
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add empty3
changeset: 1:097d2b0e17f6
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add empty2
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
Before changeset 05257fd28591, we didn't notice the
empty file that came from rev 1:
$ hg status
M empty2
$ hg commit -m merge
$ hg manifest --debug tip
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty1
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty2
b80de5d138758541c5f05265ad144ab9fa86d1db 644 empty3
$ cd ..