src/test/compile-fail/region-object-lifetime-in-coercion.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 // Test that attempts to implicitly coerce a value into an
  12 // object respect the lifetime bound on the object type.
  13
  14 trait Foo : ::std::marker::MarkerTrait {}
  15 impl<'a> Foo for &'a [u8] {}
  16
  17 // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
  18
  19 fn a(v: &[u8]) -> Box<Foo + 'static> {
  20     let x: Box<Foo + 'static> = Box::new(v);
  21     //~^ ERROR cannot infer an appropriate lifetime due to conflicting
  22     x
  23 }
  24
  25 fn b(v: &[u8]) -> Box<Foo + 'static> {
  26     Box::new(v)
  27         //~^ ERROR cannot infer an appropriate lifetime due to conflicting
  28 }
  29
  30 fn c(v: &[u8]) -> Box<Foo> {
  31     // same as previous case due to RFC 599
  32
  33     Box::new(v)
  34         //~^ ERROR cannot infer an appropriate lifetime due to conflicting
  35 }
  36
  37 fn d<'a,'b>(v: &'a [u8]) -> Box<Foo+'b> {
  38     Box::new(v)
  39         //~^ ERROR cannot infer an appropriate lifetime due to conflicting
  40 }
  41
  42 fn e<'a:'b,'b>(v: &'a [u8]) -> Box<Foo+'b> {
  43     Box::new(v) // OK, thanks to 'a:'b
  44 }
  45
  46 fn main() { }