error: expected `fn`
 --> $DIR/bad_arguments.rs:4:7
  |
4 | const NOT_A_FUNCTION: () = ();
  |       ^^^^^^^^^^^^^^

error: missing arguments
 --> $DIR/bad_arguments.rs:6:1
  |
6 | #[whaterror]
  | ^^^^^^^^^^^^
  |
  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: missing arguments
 --> $DIR/bad_arguments.rs:9:1
  |
9 | #[whaterror]
  | ^^^^^^^^^^^^
  |
  = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: expected `fn`
  --> $DIR/bad_arguments.rs:10:7
   |
10 | const NON_FUNCTION_WITHOUT_HANDLER: () = ();
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: missing arguments
  --> $DIR/bad_arguments.rs:12:1
   |
12 | #[whaterror]
   | ^^^^^^^^^^^^
   |
   = note: this error originates in an attribute macro (in Nightly builds, run with -Z macro-backtrace for more info)

error: const fns are not supported
  --> $DIR/bad_arguments.rs:13:1
   |
13 | const fn const_no_handler() {}
   | ^^^^^