Multiple max found

[dtolnay]

Looks like this is related to rust-lang/rust#42496.

   Compiling petgraph v0.4.4
warning[E0122]: trait bounds are not (yet) enforced in type definitions
   --> src/algo/mod.rs:169:1
    |
169 | type DfsSpaceType<G> where G: Visitable = DfsSpace<G::NodeId, G::Map>;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0034]: multiple applicable items in scope
   --> src/graph.rs:489:17
    |
489 |         assert!(Ix::max().index() == !0 || NodeIndex::end() != node_idx);
    |                 ^^^^^^^ multiple `max` found
    |
note: candidate #1 is defined in the trait `graph_impl::IndexType`
   --> src/graph.rs:47:5
    |
47  |     fn max() -> Self;
    |     ^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `graph_impl::IndexType::max(...)` instead
note: candidate #2 is defined in the trait `std::cmp::Ord`
    = help: to disambiguate the method call, write `std::cmp::Ord::max(...)` instead

error[E0034]: multiple applicable items in scope
   --> src/graph.rs:526:17
    |
526 |         assert!(Ix::max().index() == !0 || EdgeIndex::end() != edge_idx);
    |                 ^^^^^^^ multiple `max` found
    |
note: candidate #1 is defined in the trait `graph_impl::IndexType`
   --> src/graph.rs:47:5
    |
47  |     fn max() -> Self;
    |     ^^^^^^^^^^^^^^^^^
    = help: to disambiguate the method call, write `graph_impl::IndexType::max(...)` instead
note: candidate #2 is defined in the trait `std::cmp::Ord`
    = help: to disambiguate the method call, write `std::cmp::Ord::max(...)` instead