https://errorvault.dev/tags/interior-mutability/ Recent content in Interior-Mutability on ErrorVault — Developer Error Code Dictionary Hugo en-us Thu, 30 Apr 2026 15:08:04 +0800 https://errorvault.dev/rust/rust-e0753-function-return-interior-mutability/ Thu, 30 Apr 2026 15:08:04 +0800 https://errorvault.dev/rust/rust-e0753-function-return-interior-mutability/ <h1 id="fix-e0753-function-return-type-cannot-have-interior-mutability">Fix E0753: Function Return Type Cannot Have Interior Mutability</h1> <p>Rust&rsquo;s strict type system prevents certain patterns that would lead to undefined behavior. Error E0753 is one such case where the compiler rejects code that could create safety violations. This article dissects the error, explains why Rust blocks this pattern, and provides practical alternatives.</p> <h2 id="1-symptoms">1. Symptoms</h2> <h2 id="when-you-encounter-e0753-the-compiler-produces-an-error-message-similar-to-the-following">When you encounter E0753, the compiler produces an error message similar to the following:</h2> <p>error[E0753]: function return type cannot have an interior mutability type &ndash;&gt; src/main.rs:4:20 | 4 | fn create_cell() -&gt; Cell<!-- raw HTML omitted --> { | ^^^^^^^^^ interior mutability type | = note: <code>Cell&lt;T&gt;</code> allows modifying shared references, which requires interior mutability = note: function return types with interior mutability are not currently supported</p>