Command-Line Rust page 82
error[E0631]: type mismatch in function arguments
--> src/lib.rs:47:14
|
47 | .map(parse_positive_int)
| --- ^^^^^^^^^^^^^^^^^^ expected signature of fn(clap::Values<'_>) -> _
| |
| required by a bound introduced by this call
...
70 | fn parse_positive_int(val: &str) -> MyResult {
| --------------------------------------------------- found signature of for<'r> fn(&'r str) -> _
|
note: required by a bound in Option::<T>::map
--> /home/kenfang/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/option.rs:879:12
|
879 | F: ~const FnOnce(T) -> U,
| ^^^^^^^^^^^^^^^^^^^^^ required by this bound in Option::<T>::map