Merge pull request #442 from ehuss/kw-2018

Add 2018 edition keywords.

Author: Centril

src/keywords.md

@@ -57,6 +57,11 @@ be used as the names of:
 > KW_WHERE          : `where`\
 > KW_WHILE          : `while`
 
+The following keywords were added beginning in the 2018 edition.
+
+> **<sup>Lexer 2018+</sup>**\
+> KW_DYN            : `dyn`
+
 ## Reserved keywords
 
 These keywords aren't used yet, but they are reserved for future use. They have
@@ -78,6 +83,13 @@ them to use these keywords.
 > KW_VIRTUAL        : `virtual`\
 > KW_YIELD          : `yield`
 
+The following keywords are reserved beginning in the 2018 edition.
+
+> **<sup>Lexer 2018+</sup>**\
+> KW_ASYNC : `async`\
+> KW_AWAIT : `await`\
+> KW_TRY   : `try`
+
 ## Weak keywords
 
 These keywords have special meaning only in certain contexts. For example, it
@@ -92,12 +104,16 @@ is possible to declare a variable or method with the name `union`.
   // error[E0262]: invalid lifetime parameter name: `'static`
   fn invalid_lifetime_parameter<'static>(s: &'static str) -> &'static str { s }
   ```
-* `dyn` denotes a [trait object] and is a keyword when used in a type position
+* In the 2015 edition, [`dyn`] is a keyword when used in a type position
   followed by a path that does not start with `::`.
 
+  Beginning in the 2018 edition, `dyn` has been promoted to a strict keyword.
+
 > **<sup>Lexer</sup>**\
 > KW_UNION          : `union`\
-> KW_STATICLIFETIME : `'static`\
+> KW_STATICLIFETIME : `'static`
+>
+> **<sup>Lexer 2015</sup>**\
 > KW_DYN            : `dyn`
 
 [items]: items.html
@@ -110,4 +126,4 @@ is possible to declare a variable or method with the name `union`.
 [Crates]: crates-and-source-files.html
 [union]: items/unions.html
 [variants]: items/enumerations.html
-[trait object]: types.html#trait-objects
+[`dyn`]: types.html#trait-objects

src/types.md

@@ -676,11 +676,14 @@ For example, given a trait `Trait`, the following are all trait objects:
 * `dyn 'static + Trait`.
 * `dyn (Trait)`
 
-If the first bound of the trait object is a path that starts with `::`, then the
-`dyn` will be treated as a part of the path. The first path can be put in
-parenthesis to get around this. As such, if you want a trait object with the
-trait `::your_module::Trait`, you should write it as
-`dyn (::your_module::Trait)`.
+> **Edition Differences**: In the 2015 edition, if the first bound of the
+> trait object is a path that starts with `::`, then the `dyn` will be treated
+> as a part of the path. The first path can be put in parenthesis to get
+> around this. As such, if you want a trait object with the trait
+> `::your_module::Trait`, you should write it as `dyn (::your_module::Trait)`.
+>
+> Beginning in the 2018 edition, `dyn` is a true keyword and is not allowed in
+> paths, so the parentheses are not necessary.
 
 > Note: For clarity, it is recommended to always use the `dyn` keyword on your
 > trait objects unless your codebase supports compiling with Rust 1.26 or lower.