Fix E0791: Dereference of Raw Pointer in Const Fn

Tue, 11 Aug 2026 07:56:04 +0800

1. Symptoms

The Rust compiler emits error E0791 when it encounters raw pointer dereference operations within a const fn context. This error manifests during compilation and prevents the program from building successfully.

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

error[E0791]: dereference of raw pointer in const fn
 --> src/main.rs:4:5
  |
4 |     const fn read_value(ptr: *const i32) -> i32 {
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ const fn
...
7 |         unsafe { *ptr }
  |                  ^^^^^^ raw pointer dereference
  |
  = note: const ptr arithmetic is not stable yet
  = note: see issue #71313 <https://github.com/rust-lang/rust/issues/71313> for more information

error: aborting due to 1 previous error

The error message specifically identifies the raw pointer dereference operation (*ptr) and clarifies that the offending function is a const fn. The compiler also references an upstream tracking issue in the Rust repository, indicating this is a limitation of the current stable compiler rather than a fundamental language design choice.

Fix E0310: The Lifetime of the Destination Pointer Must Be Specified

Fri, 17 Jul 2026 19:56:04 +0800

Fix E0310: The Lifetime of the Destination Pointer Must Be Specified

Rust’s ownership and borrowing system is one of its defining features, providing memory safety guarantees at compile time without requiring garbage collection. However, when working with raw pointers in unsafe code, the compiler sometimes cannot infer the necessary lifetime relationships on its own. Error E0310 surfaces in exactly this scenario—when you invoke pointer-manipulation functions like std::ptr::read or std::ptr::write and the compiler cannot determine the validity window of the resulting reference.

Raw-Pointers on ErrorVault — Developer Error Code Dictionary

Fix E0791: Dereference of Raw Pointer in Const Fn

1. Symptoms

Fix E0310: The Lifetime of the Destination Pointer Must Be Specified

Fix E0310: The Lifetime of the Destination Pointer Must Be Specified