error[E0283]: type annotations needed
  --> $DIR/issue-77982.rs:8:10
   |
LL |     opts.get(opt.as_ref());
   |          ^^^ ------------ type must be known at this point
   |          |
   |          cannot infer type of the type parameter `Q` declared on the method `get`
   |
   = note: multiple `impl`s satisfying `String: Borrow<_>` found in the following crates: `alloc`, `core`:
           - impl Borrow<str> for String;
           - impl<T> Borrow<T> for T
             where T: ?Sized;
note: required by a bound in `HashMap::<K, V, S>::get`
  --> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL
help: consider specifying the generic argument
   |
LL |     opts.get::<Q>(opt.as_ref());
   |             +++++

error[E0283]: type annotations needed
  --> $DIR/issue-77982.rs:8:10
   |
LL |     opts.get(opt.as_ref());
   |          ^^^     ------ type must be known at this point
   |          |
   |          cannot infer type of the type parameter `Q` declared on the method `get`
   |
   = note: multiple `impl`s satisfying `String: AsRef<_>` found in the following crates: `alloc`, `std`:
           - impl AsRef<OsStr> for String;
           - impl AsRef<Path> for String;
           - impl AsRef<[u8]> for String;
           - impl AsRef<str> for String;
help: consider specifying the generic argument
   |
LL |     opts.get::<Q>(opt.as_ref());
   |             +++++

error[E0283]: type annotations needed
  --> $DIR/issue-77982.rs:13:59
   |
LL |     let ips: Vec<_> = (0..100_000).map(|_| u32::from(0u32.into())).collect();
   |                                            ---------      ^^^^
   |                                            |
   |                                            required by a bound introduced by this call
   |
   = note: multiple `impl`s satisfying `u32: From<_>` found in the `core` crate:
           - impl From<Ipv4Addr> for u32;
           - impl From<NonZeroU32> for u32;
           - impl From<bool> for u32;
           - impl From<char> for u32;
           - impl From<u16> for u32;
           - impl From<u8> for u32;
           - impl<T> From<!> for T;
           - impl<T> From<T> for T;
help: try using a fully qualified path to specify the expected types
   |
LL |     let ips: Vec<_> = (0..100_000).map(|_| u32::from(<u32 as Into<T>>::into(0u32))).collect();
   |                                                      +++++++++++++++++++++++    ~

error[E0283]: type annotations needed for `Box<T>`
  --> $DIR/issue-77982.rs:36:9
   |
LL |     let _ = ().foo();
   |         ^      --- type must be known at this point
   |
note: multiple `impl`s satisfying `(): Foo<'_, _>` found
  --> $DIR/issue-77982.rs:29:1
   |
LL | impl Foo<'static, u32> for () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | impl<'a> Foo<'a, i16> for () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider giving this pattern a type, where the type for type parameter `T` is specified
   |
LL |     let _: Box<T> = ().foo();
   |          ++++++++

error[E0283]: type annotations needed for `Box<T>`
  --> $DIR/issue-77982.rs:40:9
   |
LL |     let _ = (&()).bar();
   |         ^         --- type must be known at this point
   |
note: multiple `impl`s satisfying `&(): Bar<'_, _>` found
  --> $DIR/issue-77982.rs:32:1
   |
LL | impl<'a> Bar<'static, u32> for &'a () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL | impl<'a> Bar<'a, i16> for &'a () {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: consider giving this pattern a type, where the type for type parameter `T` is specified
   |
LL |     let _: Box<T> = (&()).bar();
   |          ++++++++

error: aborting due to 5 previous errors

For more information about this error, try `rustc --explain E0283`.