implement &T for Replacer where T: Replacer

[RinCamelia]

When attempting to call replace_all on a Regex with a str as the argument for rep(as opposed to a NoExpand), the Replacer trait implementation for str is apparently being ignored, instead falling back to the FnMut implementation. This project demonstrates the following compile error:

src\main.rs:13:23: 13:53 error: the trait `for<'r,'r> core::ops::Fn<(&'r regex::re::Captures<'r>,)>` is not implemented for the type `str` [E0277]
src\main.rs:13         true => regex.replace_all(&source, &replace.as_str()),

Where replace and source are both Strings.

Edit: just fixed the type of replace by adding as_str, as the & was not coercing the String to a str properly. See the latest commit.

[BurntSushi]

If you use replace.as_str() instead of &replace.as_str(), then your code works. The as_str method returns a &str, so &replace.as_str() has type &&str, and no impl for that exists.

I wonder if we can add a impl<'a, T: Replacer> &'a T for Replacer { ... } impl that would fix this. The standard library uses this convention AFAIK.

[BurntSushi]

I feel like it's probably not worth adding this impl unless there's a more solid reason. (It could be added in a backwards compatible manner later if we really wanted to, I think.)