Feature unification conflict because of encoding feature #861
Description
I'm building an app which is split into multiple crates. To simplify the setup, let's assume the following:
- Crate A depends on
quick-xmlwith theencodingfeature enabled - Crate B depends on
quick-xmlwith theencodingfeature not enabled and uses theAttribute::unescape_valuefunction - Crate C depends on crates A & B
When trying to build crate C, I get the following error message:
error[E0599]: no method named `unescape_value` found for struct `Attribute` in the current scope
--> B\src\lib.rs:9:7
|
6 | / Attribute {
7 | | key: QName(b"key"),
8 | | value: Cow::Borrowed(b"value"),
9 | | }.unescape_value()
| |______-^^^^^^^^^^^^^^
|
help: there is a method `decode_and_unescape_value` with a similar name, but with different arguments
--> C:\Users\Maxence\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\quick-xml-0.37.5\src\events\attributes.rs:79:5
|
79 | pub fn decode_and_unescape_value(&self, decoder: Decoder) -> XmlResult<Cow<'a, str>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
It is clear that B expects quick-xml to not have the encoding feature enabled.
Is there a way to solve this feature unification conflict?
Here's a repo to reproduce the issue: https://github.com/maxence-cornaton/quick-xml-feature-unification
For a real world scenario, imagine having crate A depending on calamine and crate B depending on mail_auth. Crate will fail to compile because calamine enables the encoding feature while mail_auth expects it to be disabled.
error[E0599]: no method named `unescape_value` found for struct `Attribute` in the current scope
--> C:\Users\Maxence\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\mail-auth-0.6.1\src\report\dmarc\parse.rs:312:48
|
312 | if let Ok(attr) = attr.unescape_value() {
| ^^^^^^^^^^^^^^
|
help: there is a method `decode_and_unescape_value` with a similar name, but with different arguments
--> C:\Users\Maxence\.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\quick-xml-0.37.5\src\events\attributes.rs:79:5
|
79 | pub fn decode_and_unescape_value(&self, decoder: Decoder) -> XmlResult<Cow<'a, str>> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^