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| author | Corey Farwell <coreyf@rwell.org> | 2017-05-20 12:08:28 -0400 |
|---|---|---|
| committer | Corey Farwell <coreyf@rwell.org> | 2017-05-20 12:08:28 -0400 |
| commit | 2d3438d35f8db4de0326f56232169b0bdbd6051c (patch) | |
| tree | 13903e508fac87cc9d7458b39ee37fec3da8c738 | |
| parent | d1f499309979fb53f4fa6d791cbfac803431579d (diff) | |
| download | rust-frewsxcv/unstable-book.tar.gz | |
Add basic Unstable Book entry for `attr_literals`.frewsxcv/unstable-book
| -rw-r--r-- | src/doc/unstable-book/src/language-features/attr-literals.md | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/doc/unstable-book/src/language-features/attr-literals.md b/src/doc/unstable-book/src/language-features/attr-literals.md index 67eee214a4f..60741a74400 100644 --- a/src/doc/unstable-book/src/language-features/attr-literals.md +++ b/src/doc/unstable-book/src/language-features/attr-literals.md @@ -6,5 +6,25 @@ The tracking issue for this feature is: [#34981] ------------------------ +At present, literals are only accepted as the value of a key-value pair in +attributes. What's more, only _string_ literals are accepted. This means that +literals can only appear in forms of `#[attr(name = "value")]` or +`#[attr = "value"]`. +The `attr_literals` unstable feature allows other types of literals to be used +in attributes. Here are some examples of attributes that can now be used with +this feature enabled: + ++```rust,ignore ++#[attr] ++#[attr(true)] ++#[attr(ident)] ++#[attr(ident, 100, true, "true", ident = 100, ident = "hello", ident(100))] ++#[attr(100)] ++#[attr(enabled = true)] ++#[enabled(true)] ++#[attr("hello")] ++#[repr(C, align = 4)] ++#[repr(C, align(4))] ++``` |