#![feature(plugin)] #![plugin(clippy)] #![deny(needless_lifetimes)] fn distinct_lifetimes<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: u8) { } //~ERROR fn distinct_and_static<'a, 'b>(_x: &'a u8, _y: &'b u8, _z: &'static u8) { } //~ERROR fn same_lifetime_on_input<'a>(_x: &'a u8, _y: &'a u8) { } // no error, same lifetime on two params fn only_static_on_input(_x: &u8, _y: &u8, _z: &'static u8) { } // no error, static involved fn in_and_out<'a>(x: &'a u8, _y: u8) -> &'a u8 { x } //~ERROR fn multiple_in_and_out_1<'a>(x: &'a u8, _y: &'a u8) -> &'a u8 { x } // no error, multiple input refs fn multiple_in_and_out_2<'a, 'b>(x: &'a u8, _y: &'b u8) -> &'a u8 { x } // no error, multiple input refs fn in_static_and_out<'a>(x: &'a u8, _y: &'static u8) -> &'a u8 { x } // no error, static involved fn deep_reference_1<'a, 'b>(x: &'a u8, _y: &'b u8) -> Result<&'a u8, ()> { Ok(x) } // no error fn deep_reference_2<'a>(x: Result<&'a u8, &'a u8>) -> &'a u8 { x.unwrap() } // no error, two input refs fn deep_reference_3<'a>(x: &'a u8, _y: u8) -> Result<&'a u8, ()> { Ok(x) } //~ERROR type Ref<'r> = &'r u8; fn lifetime_param_1<'a>(_x: Ref<'a>, _y: &'a u8) { } fn lifetime_param_2<'a, 'b: 'a>(_x: Ref<'a>, _y: &'b u8) { } //~ERROR struct X { x: u8, } impl X { fn self_and_out<'s>(&'s self) -> &'s u8 { &self.x } //~ERROR fn self_and_in_out<'s, 't>(&'s self, _x: &'t u8) -> &'s u8 { &self.x } // no error, multiple input refs fn distinct_self_and_in<'s, 't>(&'s self, _x: &'t u8) { } //~ERROR fn self_and_same_in<'s>(&'s self, _x: &'s u8) { } // no error, same lifetimes on two params } static STATIC: u8 = 1; fn main() { distinct_lifetimes(&1, &2, 3); distinct_and_static(&1, &2, &STATIC); same_lifetime_on_input(&1, &2); only_static_on_input(&1, &2, &STATIC); in_and_out(&1, 2); multiple_in_and_out_1(&1, &2); multiple_in_and_out_2(&1, &2); in_static_and_out(&1, &STATIC); let _ = deep_reference_1(&1, &2); let _ = deep_reference_2(Ok(&1)); let _ = deep_reference_3(&1, 2); lifetime_param_1(&1, &2); lifetime_param_2(&1, &2); let foo = X { x: 1 }; foo.self_and_out(); foo.self_and_in_out(&1); foo.distinct_self_and_in(&1); foo.self_and_same_in(&1); }