librustc: Make the compiler ignore purity.

For bootstrapping purposes, this commit does not remove all uses of
the keyword "pure" -- doing so would cause the compiler to no longer
bootstrap due to some syntax extensions ("deriving" in particular).
Instead, it makes the compiler ignore "pure". Post-snapshot, we can
remove "pure" from the language.

There are quite a few (~100) borrow check errors that were essentially
all the result of mutable fields or partial borrows of `@mut`. Per
discussions with Niko I think we want to allow partial borrows of
`@mut` but detect obvious footguns. We should also improve the error
message when `@mut` is erroneously reborrowed.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libsyntax/parse/lexer.rs b/src/libsyntax/parse/lexer.rs
index 09ffd79c246..90f51fe9b65 100644
--- a/src/libsyntax/parse/lexer.rs
+++ b/src/libsyntax/parse/lexer.rs
@@ -811,7 +811,7 @@ pub mod test {
             sp:span {lo:BytePos(21),hi:BytePos(23),expn_info: None}};
         check_equal (tok1,tok2);
         // the 'main' id is already read:
-        check_equal (string_reader.last_pos,BytePos(28));
+        check_equal (copy string_reader.last_pos,BytePos(28));
         // read another token:
         let tok3 = string_reader.next_token();
         let tok4 = TokenAndSpan{
@@ -819,7 +819,7 @@ pub mod test {
             sp:span {lo:BytePos(24),hi:BytePos(28),expn_info: None}};
         check_equal (tok3,tok4);
         // the lparen is already read:
-        check_equal (string_reader.last_pos,BytePos(29))
+        check_equal (copy string_reader.last_pos,BytePos(29))
     }
 
     // check that the given reader produces the desired stream