Dynamic-Dispatch on ErrorVault — Developer Error Code Dictionary

Fix E0387: Method Called on Trait Object Without Object Safety

Wed, 12 Aug 2026 12:44:04 +0800

1. Symptoms

When the Rust compiler encounters error E0387, you will see output similar to the following in your terminal:

error[E0387]: cannot call method `method_name` on a type `dyn TraitName`
  --> src/main.rs:12:5
   |
12 |     obj.method_name();
   |     ^^^^^^^^^^^^^^^^^ method `method_name` is not available on `dyn TraitName`
   |
   = note: method `method_name` has no `self` parameter
   = note: trait `TraitName` defines an item with this name, but this method cannot be dispatched to a trait object

Another variant of this error appears when you attempt to call a method that exists on the underlying type but is not part of the trait’s interface:

Fix E0232: Rust Trait Object Safety Error

Mon, 10 Aug 2026 00:44:04 +0800

1. Symptoms

When compiling Rust code that attempts to use a trait as a trait object but the trait is not object-safe, the compiler produces error E0232. This error manifests when developers attempt dynamic dispatch through dyn Trait syntax on traits containing methods that violate Rust’s object safety rules. The diagnostic message explicitly states that the trait cannot be made into an object, providing specific information about which methods prevent object safety.

Fix E0616: Attempt to Call Method Not Found on Trait Object

Wed, 15 Jul 2026 22:20:04 +0800

Fix E0616: Attempt to Call Method Not Found on Trait Object

Rust’s trait system provides powerful abstraction capabilities through both static and dynamic dispatch. When working with trait objects via dyn Trait, you encounter a fundamental limitation: only the methods declared in the trait definition are available at runtime. Error E0616 surfaces when your code attempts to call a method that exists on the underlying concrete type but was not included in the trait definition. This creates a clear separation between what the concrete type can do and what the trait object can expose, enforcing the boundaries of dynamic dispatch.

Fix E0376: Cannot Use Unsafe Trait as Trait Object

Mon, 08 Jun 2026 10:20:04 +0800

Fix E0376: Cannot Use Unsafe Trait as Trait Object

The Rust compiler error E0376 occurs when attempting to create a trait object (dyn Trait) from the Unsafe trait. The Unsafe trait is fundamentally incompatible with dynamic dispatch because it represents a marker trait with special semantic meaning that cannot be safely abstracted at runtime.

1. Symptoms

When you attempt to use the Unsafe trait with dynamic dispatch syntax, the compiler produces a clear error message: