Merge pull request rust-lang#1042 from LukasKalbertodt/patch-1

Clarify "string continue" for (byte) string literals

Author: ehuss

Diff for: src/tokens.md

@@ -148,18 +148,28 @@ which must be _escaped_ by a preceding `U+005C` character (`\`).
 Line-breaks are allowed in string literals. A line-break is either a newline
 (`U+000A`) or a pair of carriage return and newline (`U+000D`, `U+000A`). Both
 byte sequences are normally translated to `U+000A`, but as a special exception,
-when an unescaped `U+005C` character (`\`) occurs immediately before the
-line-break, then the `U+005C` character, the line-break, and all whitespace at the
-beginning of the next line are ignored. Thus `a` and `b` are equal:
+when an unescaped `U+005C` character (`\`) occurs immediately before a line
+break, then the line break character(s), and all immediately following
+` ` (`U+0020`), `\t` (`U+0009`), `\n` (`U+000A`) and `\r` (`U+0000D`) characters
+are ignored. Thus `a`, `b` and `c` are equal:
 
 ```rust
 let a = "foobar";
 let b = "foo\
          bar";
+let c = "foo\
 
-assert_eq!(a,b);
+     bar";
+
+assert_eq!(a, b);
+assert_eq!(b, c);
 ```
 
+> Note: Rust skipping additional newlines (like in example `c`) is potentially confusing and
+> unexpected. This behavior may be adjusted in the future. Until a decision is made, it is
+> recommended to avoid relying on this, i.e. skipping multiple newlines with line continuations.
+> See [this issue](https://github.com/rust-lang/reference/pull/1042) for more information.
+
 #### Character escapes
 
 Some additional _escapes_ are available in either character or non-raw string