```
warning: the type of this value must be known in this context
--> src/lib.rs:312:32
|
312 | ptr::copy(p, p.offset(1), len - index);
| ^^^^^^
|
= note: #[warn(tyvar_behind_raw_pointer)] on by default
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #46906 <https://github.com/rust-lang/rust/issues/46906>
```
Instead of being vague about it, we can promise it.
We continue to be a bit vague in ArrayString::set_len. I don't see how
to add a char boundary check in ArrayString::set_len unfortunately.
It's a tricky issue, checking char boundaries requires reading the
memory of the string, and we don't even know if the user of set_len has
initialized that area of memory yet (but they hopefully did).
We have to use the "SetLenOnDrop" pattern (see stdlib Vec) here.
Keep the length in a separate variable, write it back on scope exit. To
help the compiler with alias analysis and stuff. We update the length
to handle panic in the iteration of the user's iterator, without
dropping any elements on the floor.
Note: This code was tested without the scope guard using the new option
-Zmutable-noalias, which had no effect here.
benchmark:
```
name before.txt ns/iter after.txt ns/iter diff ns/iter diff %
extend_with_constant 280 (1828 MB/s) 74 (6918 MB/s) -206 -73.57%
extend_with_range 1,285 (398 MB/s) 979 (522 MB/s) -306 -23.81%
extend_with_slice 29 (17655 MB/s) 14 (36571 MB/s) -15 -51.72%
```
- Add try_insert / try_remove to be the old fallible variants that
return errors
- Insert that pushes out if full does no longer exist -- full vec is an
error
This implements serde support under the optional 'serde' feature, and adds unit tests to test said support.
https://serde.rs/unit-testing.html used as a guide for the unit tests - using 'serde_test' makes for much
less boilerplate here, but it does require that the project have a non-optional dev dependency on 'serde_test'.
bluss