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Merge pull request #1095 from alexreg/master
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Added section on compatibility and subsection on raw identifiers
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frewsxcv authored Aug 22, 2018
2 parents 38b3a3f + 9bbef9d commit e0f7ce1
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7 changes: 5 additions & 2 deletions src/SUMMARY.md
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- [Integration testing](testing/integration_testing.md)
- [Dev-dependencies](testing/dev_dependencies.md)

- [Unsafe Operations](unsafe.md)

- [Compatibility](compatibility.md)
- [Raw identifiers](compatibility/raw_identifiers.md)

- [Meta](meta.md)
- [Documentation](meta/doc.md)

- [Unsafe Operations](unsafe.md)
7 changes: 7 additions & 0 deletions src/compatibility.md
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# Compatibility

The Rust language is fastly evolving, and because of this certain compatibility
issues can arise, despite efforts to ensure forwards-compatibility wherever
possible.

* [Raw identifiers](compatibility/raw_identifiers.md)
42 changes: 42 additions & 0 deletions src/compatibility/raw_identifiers.md
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# Raw identifiers

Rust, like many programming languages, has the concept of "keywords".
These identifiers mean something to the language, and so you cannot use them in
places like variable names, function names, and other places.
Raw identifiers let you use keywords where they would not normally be allowed.
This is particularly useful when Rust introduces new keywords, and a library
using an older edition of Rust has a variable or function with the same name
as a keyword introduced in a newer edition.

For example, consider a crate `foo` compiled with the 2015 edition of Rust that
exports a function named `try`. This keyword is reserved for a new feature in
the 2018 edition, so without raw identifiers, we would have no way to name the
function.

```rust,ignore
extern crate foo;
fn main() {
foo::try();
}
```

You'll get this error:

```text
error: expected identifier, found keyword `try`
--> src/main.rs:4:4
|
4 | foo::try();
| ^^^ expected identifier, found keyword
```

You can write this with a raw identifier:

```rust,ignore
extern crate foo;
fn main() {
foo::r#try();
}
```
6 changes: 4 additions & 2 deletions src/index.md
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- [Testing](testing.html) - All sorts of testing in Rust.

- [Meta](meta.html) - Documentation, Benchmarking.

- [Unsafe Operations](unsafe.html)

- [Compatibility](compatibility.html)

- [Meta](meta.html) - Documentation, Benchmarking.


[rust]: https://www.rust-lang.org/
[install]: https://www.rust-lang.org/install.html
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