String/character escape rules do not match the reference

[keleshev]

The reference does not allow \' escape inside strings, and neither \" inside character literals. This makes sense, as the backslash is redundant in these cases. However, the compiler accepts both: http://is.gd/CDBzp1

[petrochenkov]

The reference is incomplete, the full list is

\xFF (exactly 2 hex digits)
\u{FFFF} (from 1 to 6 (inclusively) hex digits)
\n
\r
\t
\0
\"
\'
\\

[keleshev]

@petrochenkov the reference includes all of your examples, except:

1. no \0
2. \' is restricted to character literals
3. \" is restricted to string literals

[keleshev]

And I think this restriction is made on purpose. It does not make sense to have \' inside string literal, because ' (single quote) works fine.

[steveklabnik]

cc @rust-lang/lang is the compiler too accepting here, or is this a docs bug?

[nrc]

/me shrugs
seems either position is reasonable. I don't think it's worth a breaking change to 'fix' the compiler unless there is an example of this being dangerous. I guess it might be bad if the user expects \' to be \' not ' and so doesn't escape the \

[nikomatsakis]

I agree with @nrc. I think it'd actually be more confusing to have the same sequence (e.g., \") mean different things in character vs string literals. Or at least I'd find it confusing.

[steveklabnik]

Okay! Moving to docs bug then.