// 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. pub fn foo(params: Option<&[&str]>) -> usize { params.unwrap().first().unwrap().len() } fn main() { let name = "Foo"; let x = Some(&[name]); let msg = foo(x); //~^ ERROR mismatched types //~| expected type `std::option::Option<&[&str]>` //~| found type `std::option::Option<&[&str; 1]>` //~| expected slice, found array of 1 elements assert_eq!(msg, 3); }