librustc: Always parse `macro!()`/`macro![]` as expressions if not

followed by a semicolon.

This allows code like `vec![1i, 2, 3].len();` to work.

This breaks code that uses macros as statements without putting
semicolons after them, such as:

    fn main() {
        ...
        assert!(a == b)
        assert!(c == d)
        println(...);
    }

It also breaks code that uses macros as items without semicolons:

    local_data_key!(foo)

    fn main() {
        println("hello world")
    }

Add semicolons to fix this code. Those two examples can be fixed as
follows:

    fn main() {
        ...
        assert!(a == b);
        assert!(c == d);
        println(...);
    }

    local_data_key!(foo);

    fn main() {
        println("hello world")
    }

RFC #378.

Closes #18635.

[breaking-change]

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/io/net/ip.rs b/src/libstd/io/net/ip.rs
index 092410fbc8e..5a3f5bd4668 100644
--- a/src/libstd/io/net/ip.rs
+++ b/src/libstd/io/net/ip.rs
@@ -478,7 +478,7 @@ fn resolve_socket_addr(s: &str, p: u16) -> IoResult<Vec<SocketAddr>> {
 }
 
 fn parse_and_resolve_socket_addr(s: &str) -> IoResult<Vec<SocketAddr>> {
-    macro_rules! try_opt(
+    macro_rules! try_opt {
         ($e:expr, $msg:expr) => (
             match $e {
                 Some(r) => r,
@@ -489,7 +489,7 @@ fn parse_and_resolve_socket_addr(s: &str) -> IoResult<Vec<SocketAddr>> {
                 })
             }
         )
-    )
+    }
 
     // split the string by ':' and convert the second part to u16
     let mut parts_iter = s.rsplitn(2, ':');