rust/src/libcollections/macros.rs
Patrick Walton ddb2466f6a 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]
2014-12-18 12:09:07 -05:00

24 lines
788 B
Rust

// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![macro_escape]
/// Creates a `std::vec::Vec` containing the arguments.
macro_rules! vec {
($($e:expr),*) => ({
// leading _ to allow empty construction without a warning.
let mut _temp = ::vec::Vec::new();
$(_temp.push($e);)*
_temp
});
($($e:expr),+,) => (vec!($($e),+))
}