Error code E0077

A tuple struct's element isn't a machine type when using the #[simd] attribute.

Erroneous code example:

#![allow(unused)] #![feature(repr_simd)] fn main() { #[repr(simd)] struct Bad([String; 2]); // error! }

When using the #[simd] attribute on a tuple struct, the elements in the tuple must be machine types so SIMD operations can be applied to them.

Fixed example:

#![allow(unused)] #![feature(repr_simd)] fn main() { #[repr(simd)] struct Good([u32; 4]); // ok! }