Fix E0059: Cannot Provide Explicit Generic Parameters in Impl Block

Sun, 02 Aug 2026 03:08:04 +0800

1. Symptoms

The Rust compiler produces error E0059 when you attempt to provide explicit generic parameters where they are not permitted by the language specification. This error manifests in several distinct patterns that share a common theme: mixing explicit generic argument syntax with contexts that expect deferred type resolution.

When this error occurs, you will see output similar to the following in your compiler output:

error[E0059]: cannot provide explicit generic parameters when using `impl Trait`
 --> src/main.rs:4:12
  |
4 | impl<T: Clone> MyTrait for Foo<T> {}
  |            ^^^^^^^^
  |
  = note: explicit generic parameters cannot be used with `impl Trait` in this position

A different manifestation appears when working with function pointers in trait bounds:

E0059 on ErrorVault — Developer Error Code Dictionary

Fix E0059: Cannot Provide Explicit Generic Parameters in Impl Block

1. Symptoms