trpl/traits: Make error message consistent with source code snippet

[peferron]

The source code snippet uses "whatever".as_bytes() but the compilation error message uses b"whatever". Both should be consistent with each other.

r? @steveklabnik

[rust-highfive]

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[alexcrichton]

In this case I think it's actually somewhat more idiomatic to use the b"..." syntax, perhaps the code snippet could be updated instead to use that?

[peferron]

As a Rust beginner who started two days ago, I'll take your word for b"..." being more idiomatic, but it would likely need a short explanation. "...".as_bytes() is self-explanatory and already introduced in the preceding Strings section, but b"..." would have sent me googling to confirm that it's indeed shorthand for "...".as_bytes().

If b"..." is better then please confirm and I'll update the PR and add a short explanation.

[alexcrichton]

Ah yeah I think it'd be fine to add a few words saying that b".." is a byte-string and distinct from &str

[peferron]

@alexcrichton How about now?

[alexcrichton]

@bors: r+ a10d243 rollup

Thanks!

[steveklabnik]

Thank you!