error: casting i32 to i64 may become silently lossy if types change
 --> $DIR/types.rs:9:23
  |
9 |     let c_i64 : i64 = c as i64;
  |                       ^^^^^^^^ help: try: `i64::from(c)`
  |
  = note: `-D cast-lossless` implied by `-D warnings`

error: aborting due to previous error