error[E0261]: use of undeclared lifetime name `'a` --> $DIR/ice-unexpected-inference-var-122549.rs:5:70 | LL | fn const_chunks_exact(&self) -> ConstChunksExact<'a, T, { N }>; | ^^ undeclared lifetime | help: consider introducing lifetime `'a` here | LL | fn const_chunks_exact<'a, const N: usize>(&self) -> ConstChunksExact<'a, T, { N }>; | +++ help: consider introducing lifetime `'a` here | LL | trait ConstChunksExactTrait<'a, T> { | +++ error[E0261]: use of undeclared lifetime name `'a` --> $DIR/ice-unexpected-inference-var-122549.rs:11:34 | LL | struct ConstChunksExact<'rem, T: 'a, const N: usize> {} | - ^^ undeclared lifetime | | | help: consider introducing lifetime `'a` here: `'a,` error[E0046]: not all trait items implemented, missing: `const_chunks_exact` --> $DIR/ice-unexpected-inference-var-122549.rs:9:1 | LL | fn const_chunks_exact(&self) -> ConstChunksExact<'a, T, { N }>; | ------------------------------------------------------------------------------- `const_chunks_exact` from trait ... LL | impl ConstChunksExactTrait for [T] {} | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `const_chunks_exact` in implementation error[E0392]: lifetime parameter `'rem` is never used --> $DIR/ice-unexpected-inference-var-122549.rs:11:25 | LL | struct ConstChunksExact<'rem, T: 'a, const N: usize> {} | ^^^^ unused lifetime parameter | = help: consider removing `'rem`, referring to it in a field, or using a marker such as `PhantomData` error[E0392]: type parameter `T` is never used --> $DIR/ice-unexpected-inference-var-122549.rs:11:31 | LL | struct ConstChunksExact<'rem, T: 'a, const N: usize> {} | ^ unused type parameter | = help: consider removing `T`, referring to it in a field, or using a marker such as `PhantomData` error[E0207]: the const parameter `N` is not constrained by the impl trait, self type, or predicates --> $DIR/ice-unexpected-inference-var-122549.rs:15:13 | LL | impl<'a, T, const N: usize> Iterator for ConstChunksExact<'a, T, {}> { | ^^^^^^^^^^^^^^ unconstrained const parameter | = note: expressions using a const parameter must map each value to a distinct output value = note: proving the result of expressions other than the parameter are unique is not supported error[E0308]: mismatched types --> $DIR/ice-unexpected-inference-var-122549.rs:15:66 | LL | impl<'a, T, const N: usize> Iterator for ConstChunksExact<'a, T, {}> { | ^^ expected `usize`, found `()` error: aborting due to 7 previous errors Some errors have detailed explanations: E0046, E0207, E0261, E0308, E0392. For more information about an error, try `rustc --explain E0046`.