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 for String; - impl Borrow for T where T: ?Sized; note: required by a bound in `HashMap::::get` --> $SRC_DIR/std/src/collections/hash/map.rs:LL:COL help: consider specifying the generic argument | LL | opts.get::(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 for String; - impl AsRef for String; - impl AsRef<[u8]> for String; - impl AsRef for String; help: consider specifying the generic argument | LL | opts.get::(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 for u32; - impl From for u32; - impl From for u32; - impl From for u32; - impl From for u32; - impl From for u32; - impl From for T; - impl From for T; help: try using a fully qualified path to specify the expected types | LL | let ips: Vec<_> = (0..100_000).map(|_| u32::from(>::into(0u32))).collect(); | +++++++++++++++++++++++ ~ error[E0283]: type annotations needed for `Box` --> $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 = ().foo(); | ++++++++ error[E0283]: type annotations needed for `Box` --> $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 = (&()).bar(); | ++++++++ error: aborting due to 5 previous errors For more information about this error, try `rustc --explain E0283`.