ICE using <T as Fn()>::call

[arielb1]

Meta

rustc 1.17.0-nightly (c49d10207 2017-02-07)

STR

#![feature(fn_traits)]

fn main() {
    <fn() as Fn()>::call;
}

Expected Result

Code works

Actual Result

error: internal compiler error: /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/librustc_typeck/check/mod.rs:4507: parenthesized parameters cannot appear in ExprPath
 --> <anon>:4:5
  |
4 |     <fn() as Fn()>::call;
  |     ^^^^^^^^^^^^^^^^^^^^

note: the compiler unexpectedly panicked. this is a bug.

note: we would appreciate a bug report: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md#bug-reports

thread 'rustc' panicked at 'Box<Any>', /buildslave/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/librustc_errors/lib.rs:376
note: Run with `RUST_BACKTRACE=1` for a backtrace.

cc @eddyb

[eminence]

Bug triage: on current nightly (rustc 1.23.0-nightly (e97ba8328 2017-11-25)), this no longer is an ICE, but yields the following error:

error[E0229]: associated type bindings are not allowed here
 --> a.rs:4:16
  |
4 |     <fn() as Fn()>::call;
  |                ^^ associated type not allowed here

error: aborting due to previous error