error[E0271]: type mismatch resolving `::Output == i64` --> $DIR/dont-probe-missing-item-name-4.rs:21:13 | LL | problem(MyServerFn {}); | ------- ^^^^^^^^^^^^^ type mismatch resolving `::Output == i64` | | | required by a bound introduced by this call | note: expected this to be `i64` --> $DIR/dont-probe-missing-item-name-4.rs:10:27 | LL | type Output = (); | ^^ ... LL | f! {} | ----- in this macro invocation note: required by a bound in `problem` --> $DIR/dont-probe-missing-item-name-4.rs:18:24 | LL | fn problem>(_: T) {} | ^^^^^^^^^^^^ required by this bound in `problem` = note: this error originates in the macro `f` (in Nightly builds, run with -Z macro-backtrace for more info) error: aborting due to 1 previous error For more information about this error, try `rustc --explain E0271`.