"internal compiler error" while trying to implement the Fibbonaci function with memoziation.

[geekynils]

fn memFib(n: int) -> int {
    let memo = [0, 1];
    let fib = |n: int| -> int { 
        match memo.len() as int { 
            0 .. n - 1 => memo[n],
            _          => memFib(n - 1) + memFib(n - 2)
        } 
    };
}

fn main() {
    io::println(fmt!("%d", memFib(7)));
}

$ RUST_LOG=rustc=1,::rt::backtrace rust run Fail.rs
rust: task failed at 'Bad operands for binary', /Users/nils/Develop/rust-0.6/src/librustc/middle/const_eval.rs:251
error: internal compiler error: unexpected failure
note: the compiler hit an unexpected failure path. this is a bug
note: try running with RUST_LOG=rustc=1,::rt::backtrace to get further details and report the results to github.com/mozilla/rust/issues
rust: task failed at 'explicit failure', /Users/nils/Develop/rust-0.6/src/librustc/rustc.rc:357
rust: domain main @0x7fa4d900c210 root task failed

[jdm]

I suspect this occurs because we only handle literals and (maybe) constants in range patterns.

[jdm]

Likely the same issue as #6047.

[Aatch]

This no longer even parses: unexpected token: 'n'