Fix E0227: Automatic Dereferencing Not Possible for impl Trait Methods

Mon, 03 Aug 2026 19:56:04 +0800

1. Symptoms

The Rust compiler emits error E0227 when it encounters a situation where automatic dereferencing would be required to resolve a method call, but the compiler cannot perform this dereference automatically. This error is specific to impl Trait return types and occurs during the method resolution phase of compilation.

The error manifests with a message similar to the following:

error[E0227]: automatic dereferencing is not possible for methods of impl Trait types
  --> src/main.rs:10:5
   |
10 |     instance.method_on_reference();
   |            ^^^^^^^^^^^^^^^^^^^^^ cannotautoderef due to impl Trait
   |
   = note: Methods of impl Trait types cannot be called through automatic dereferencing.

In practice, you will encounter this error when working with functions that return impl Trait and you attempt to call methods that require dereferencing the returned type to match the method’s self parameter. The compiler provides this error because the concrete type behind the impl Trait is not known at the call site, making automatic dereferencing impossible to perform safely.

Dereferencing on ErrorVault — Developer Error Code Dictionary

Fix E0227: Automatic Dereferencing Not Possible for impl Trait Methods

1. Symptoms