Watch out for modules privacy when proposing traits to associate with an item

[catenacyber]

Working on suricata OISF/suricata#7150

The current output is:

error[E0599]: no associated item named `MAX` found for type parameter `T` in the current scope
   --> src/detect.rs:109:18
    |
109 |         x < <T>::MAX
    |                  ^^^ associated item not found in `T`
    |
    = help: items from traits can only be used if the type parameter is bounded by the trait
help: the following traits define an item `MAX`, perhaps you need to restrict type parameter `T` with one of them:
    |
104 | fn detect_parse_uint_start_greater<T: lexical_core::util::num::Float + std::str::FromStr>(i: &str) -> IResult<&str, DetectUintData<T>> {
    |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
104 | fn detect_parse_uint_start_greater<T: lexical_core::util::num::Integer + std::str::FromStr>(i: &str) -> IResult<&str, DetectUintData<T>> {

This proposal looks interesting but when It tried it, I was disappointed :

error[E0603]: module `util` is private --> src/detect.rs:41:51 | 41 | fn detect_parse_uint_start_equal<T: lexical_core::util::num::Integer>(i: &str) -> IResult<&str, DetectUintData<T>> { | ^^^^ private module | note: the module `util` is defined here --> /Users/catena/.cargo/registry/src/github.com-1ecc6299db9ec823/lexical-core-0.7.6/src/lib.rs:189:1

<!-- The following is not always necessary. -->
Ideally the output should look like:

"the following traits define an item MAX, you could restrict the type parameter, but it is private so you can't"?

[m-ou-se]

This shows the same issue, without any dependencies other than std:

fn main() {
    struct A;
    A.is_minus_one();
}

error[E0599]: no method named `is_minus_one` found for struct `A` in the current scope
 --> src/main.rs:3:7
  |
2 |     struct A;
  |     --------- method `is_minus_one` not found for this
3 |     A.is_minus_one();
  |       ^^^^^^^^^^^^ method not found in `A`
  |
  = help: items from traits can only be used if the trait is implemented and in scope
  = note: the following trait defines an item `is_minus_one`, perhaps you need to implement it:
          candidate #1: `std::sys::unix::IsMinusOne`

std::sys::unix::IsMinusOne is an internal implementation detail of std. It's declared as pub trait IsMinusOne, but it's not publicly accessible, since std::sys isn't public.