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+An invalid cast was attempted.
+
+Erroneous code examples:
+
+```compile_fail,E0605
+let x = 0u8;
+x as Vec<u8>; // error: non-primitive cast: `u8` as `std::vec::Vec<u8>`
+
+// Another example
+
+let v = core::ptr::null::<u8>(); // So here, `v` is a `*const u8`.
+v as &u8; // error: non-primitive cast: `*const u8` as `&u8`
+```
+
+Only primitive types can be cast into each other. Examples:
+
+```
+let x = 0u8;
+x as u32; // ok!
+
+let v = core::ptr::null::<u8>();
+v as *const i8; // ok!
+```
+
+For more information about casts, take a look at the Type cast section in
+[The Reference Book][1].
+
+[1]: https://doc.rust-lang.org/reference/expressions/operator-expr.html#type-cast-expressions