Fix E0210: Type Name is Reserved as a Foreign Type Name

Sat, 25 Jul 2026 19:56:04 +0800

1. Symptoms

The Rust compiler emits error E0210 when you attempt to define a struct, enum, union, or type alias using a name that is reserved for foreign type bindings. This error typically manifests during compilation and prevents the code from building successfully.

Shell Output

When E0210 is triggered, the compiler produces output similar to the following:

error[E0210]: type name `c_int` is reserved as a foreign type name
  --> src/main.rs:3:1
  |
3  | struct c_int { value: i32 }
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^ this name is reserved for foreign types
  |
  = note: these names are reserved through the FFI unsafe guidelines:
          https://doc.rust-lang.org/nomicon/ffi.html

In some cases, the error message might reference a different reserved name:

E0210 on ErrorVault — Developer Error Code Dictionary

Fix E0210: Type Name is Reserved as a Foreign Type Name

1. Symptoms

Shell Output