error[E0658]: `while` is not allowed in a `const`
  --> $DIR/infinite_loop.rs:7:9
   |
LL | /         while n != 0 {
LL | |
LL | |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
LL | |
LL | |
LL | |         }
   | |_________^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/52000
   = help: add `#![feature(const_loop)]` to the crate attributes to enable
   = help: add `#![feature(const_if_match)]` to the crate attributes to enable

error[E0658]: `if` is not allowed in a `const`
  --> $DIR/infinite_loop.rs:9:17
   |
LL |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = note: for more information, see https://github.com/rust-lang/rust/issues/49146
   = help: add `#![feature(const_if_match)]` to the crate attributes to enable

warning: Constant evaluating a complex constant, this might take some time
  --> $DIR/infinite_loop.rs:4:18
   |
LL |       let _ = [(); {
   |  __________________^
LL | |
LL | |         let mut n = 113383; // #20 in https://oeis.org/A006884
LL | |         while n != 0 {
...  |
LL | |         n
LL | |     }];
   | |_____^

error[E0080]: evaluation of constant value failed
  --> $DIR/infinite_loop.rs:9:20
   |
LL |             n = if n % 2 == 0 { n/2 } else { 3*n + 1 };
   |                    ^^^^^^^^^^ duplicate interpreter state observed here, const evaluation will never terminate

error: aborting due to 3 previous errors

Some errors have detailed explanations: E0080, E0658.
For more information about an error, try `rustc --explain E0080`.