Doc: http://static.rust-lang.org/doc/tutorial-ffi.html sample does not compile

[mikedilger]

New to rust, I can't debug it, but I tried the following changes to main without figuring it out:

fn main() {
    let args: ~[~str] = core::os::args();
    assert!(args.len()>1);

    /* This works */
    io::println( args[1] );

    /* This works too */
    io::println( sha1( ~"xyz" ) );

    /* This gives a compile error:
    "moving out of immutable vec content" */
    io::println( sha1( args[1] ) );
}

My rust compiled from git commit 5f13e9c

[thestinger]

This is because it passes by-value, which will move values with destructors. It has to be passed as a slice or copied because os::args is immutable. I rewrote the FFI tutorial but it hasn't been regenerated by the documentation bot yet. Until then you can use https://github.com/mozilla/rust/blob/incoming/doc/tutorial-ffi.md