compiler/rustc_error_codes/src/error_codes/E0161.md

   1 A value was moved whose size was not known at compile time.
   2
   3 Erroneous code example:
   4
   5 ```compile_fail,E0161
   6 #![feature(box_syntax)]
   7
   8 fn main() {
   9     let array: &[isize] = &[1, 2, 3];
  10     let _x: Box<[isize]> = box *array;
  11     // error: cannot move a value of type [isize]: the size of [isize] cannot
  12     //        be statically determined
  13 }
  14 ```
  15
  16 In Rust, you can only move a value when its size is known at compile time.
  17
  18 To work around this restriction, consider "hiding" the value behind a reference:
  19 either `&x` or `&mut x`. Since a reference has a fixed size, this lets you move
  20 it around as usual. Example:
  21
  22 ```
  23 #![feature(box_syntax)]
  24
  25 fn main() {
  26     let array: &[isize] = &[1, 2, 3];
  27     let _x: Box<&[isize]> = box array; // ok!
  28 }
  29 ```