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+A cast between a thin and a fat pointer was attempted.
+
+Erroneous code example:
+
+```compile_fail,E0607
+let v = core::ptr::null::<u8>();
+v as *const [u8];
+```
+
+First: what are thin and fat pointers?
+
+Thin pointers are "simple" pointers: they are purely a reference to a memory
+address.
+
+Fat pointers are pointers referencing Dynamically Sized Types (also called
+DSTs). DSTs don't have a statically known size, therefore they can only exist
+behind some kind of pointer that contains additional information. For example,
+slices and trait objects are DSTs. In the case of slices, the additional
+information the fat pointer holds is their size.
+
+To fix this error, don't try to cast directly between thin and fat pointers.
+
+For more information about type casts, take a look at the section of the
+[The Rust Reference][1] on type cast expressions.
+
+[1]: https://doc.rust-lang.org/reference/expressions/operator-expr.html#type-cast-expressions