gistfile1.txt

#[feature(macro_rules)];


struct Object;

impl Object {
    pub fn is_blue(&self) -> bool {true}
    pub fn is_small(&self) -> bool {true}
    pub fn is_heavy(&self) -> bool {true}
}

macro_rules! is(
    ($object:ident, $($property:ident),+) => (
        ($($object.concat_idents!(is_, $property))&&*)
    )
)


fn main() {
    let obj = Object;
    // should be expanded to: (obj.is_blue() && obj.is_small() && obj.is_heavy())
    if is!(obj, blue, small, heavy) {}
    // macros.rs:14:32: 14:33 error: expected one of `,`, `)` but found `!`
    // macros.rs:14         ($($object.concat_idents!(is_, $property)),*)
    //                                              ^
    // task '<unnamed>' failed at 'explicit failure', /home/thomas/opt/code/rust/src/libsyntax/diagnostic.rs:75
    // task '<unnamed>' failed at 'explicit failure', /home/thomas/opt/code/rust/src/librustc/rustc.rs:396
}