#### Note: this error code is no longer emitted by the compiler. In-band lifetimes were mixed with explicit lifetime binders. Erroneous code example: ```ignore (feature got removed) #![feature(in_band_lifetimes)] fn foo<'a>(x: &'a u32, y: &'b u32) {} // error! struct Foo<'a> { x: &'a u32 } impl Foo<'a> { fn bar<'b>(x: &'a u32, y: &'b u32, z: &'c u32) {} // error! } impl<'b> Foo<'a> { // error! fn baz() {} } ``` In-band lifetimes cannot be mixed with explicit lifetime binders. For example: ``` fn foo<'a, 'b>(x: &'a u32, y: &'b u32) {} // ok! struct Foo<'a> { x: &'a u32 } impl<'a> Foo<'a> { fn bar<'b,'c>(x: &'a u32, y: &'b u32, z: &'c u32) {} // ok! } impl<'a> Foo<'a> { // ok! fn baz() {} } ```