error[E0635]: unknown feature `const_fn_trait_ref_impls`
  --> $DIR/fn_trait_refs.rs:3:12
   |
LL | #![feature(const_fn_trait_ref_impls)]
   |            ^^^^^^^^^^^^^^^^^^^^^^^^

error[E0635]: unknown feature `const_cmp`
  --> $DIR/fn_trait_refs.rs:7:12
   |
LL | #![feature(const_cmp)]
   |            ^^^^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:13:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:13:24
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |                        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:13:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:13:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:13:24
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |                        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:20:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:20:27
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |                           ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:20:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:20:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:20:27
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |                           ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:27:8
   |
LL |     T: ~const FnOnce<()>,
   |        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:27:8
   |
LL |     T: ~const FnOnce<()>,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:27:8
   |
LL |     T: ~const FnOnce<()>,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:34:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:34:24
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |                        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:34:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:34:8
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:34:24
   |
LL |     T: ~const Fn<()> + ~const Destruct,
   |                        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:48:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:48:27
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |                           ^^^^^^

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:48:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:48:8
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |        ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error: `~const` can only be applied to `#[const_trait]` traits
  --> $DIR/fn_trait_refs.rs:48:27
   |
LL |     T: ~const FnMut<()> + ~const Destruct,
   |                           ^^^^^^
   |
   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`

error[E0015]: cannot call non-const operator in constants
  --> $DIR/fn_trait_refs.rs:70:17
   |
LL |         assert!(test_one == (1, 1, 1));
   |                 ^^^^^^^^^^^^^^^^^^^^^
   |
   = note: calls in constants are limited to constant functions, tuple structs and tuple variants

error[E0015]: cannot call non-const operator in constants
  --> $DIR/fn_trait_refs.rs:73:17
   |
LL |         assert!(test_two == (2, 2));
   |                 ^^^^^^^^^^^^^^^^^^
   |
   = note: calls in constants are limited to constant functions, tuple structs and tuple variants

error[E0015]: cannot call non-const closure in constant functions
  --> $DIR/fn_trait_refs.rs:15:5
   |
LL |     f()
   |     ^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
   |
LL |     T: ~const Fn<()> + ~const Destruct + ~const Fn(),
   |                                        +++++++++++++

error[E0493]: destructor of `T` cannot be evaluated at compile-time
  --> $DIR/fn_trait_refs.rs:11:23
   |
LL | const fn tester_fn<T>(f: T) -> T::Output
   |                       ^ the destructor for this type cannot be evaluated in constant functions
...
LL | }
   | - value is dropped here

error[E0015]: cannot call non-const closure in constant functions
  --> $DIR/fn_trait_refs.rs:22:5
   |
LL |     f()
   |     ^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
   |
LL |     T: ~const FnMut<()> + ~const Destruct + ~const FnMut(),
   |                                           ++++++++++++++++

error[E0493]: destructor of `T` cannot be evaluated at compile-time
  --> $DIR/fn_trait_refs.rs:18:27
   |
LL | const fn tester_fn_mut<T>(mut f: T) -> T::Output
   |                           ^^^^^ the destructor for this type cannot be evaluated in constant functions
...
LL | }
   | - value is dropped here

error[E0015]: cannot call non-const closure in constant functions
  --> $DIR/fn_trait_refs.rs:29:5
   |
LL |     f()
   |     ^^^
   |
   = note: calls in constant functions are limited to constant functions, tuple structs and tuple variants
help: consider further restricting this bound
   |
LL |     T: ~const FnOnce<()> + ~const FnOnce(),
   |                          +++++++++++++++++

error[E0493]: destructor of `T` cannot be evaluated at compile-time
  --> $DIR/fn_trait_refs.rs:32:21
   |
LL | const fn test_fn<T>(mut f: T) -> (T::Output, T::Output, T::Output)
   |                     ^^^^^ the destructor for this type cannot be evaluated in constant functions
...
LL | }
   | - value is dropped here

error[E0493]: destructor of `T` cannot be evaluated at compile-time
  --> $DIR/fn_trait_refs.rs:46:25
   |
LL | const fn test_fn_mut<T>(mut f: T) -> (T::Output, T::Output)
   |                         ^^^^^ the destructor for this type cannot be evaluated in constant functions
...
LL | }
   | - value is dropped here

error: aborting due to 34 previous errors

Some errors have detailed explanations: E0015, E0493, E0635.
For more information about an error, try `rustc --explain E0015`.