error[E0010]: allocations are not allowed in constants
  --> $DIR/E0010-teach.rs:5:23
   |
LL | const CON: Vec<i32> = vec![1, 2, 3];
   |                       ^^^^^^^^^^^^^ allocation not allowed in constants
   |
   = note: The value of statics and constants must be known at compile time, and they live for the entire lifetime of a program. Creating a boxed value allocates memory on the heap at runtime, and therefore cannot be done at compile time.
   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0015]: cannot call non-const fn `slice::<impl [i32]>::into_vec::<std::alloc::Global>` in constants
  --> $DIR/E0010-teach.rs:5:23
   |
LL | const CON: Vec<i32> = vec![1, 2, 3];
   |                       ^^^^^^^^^^^^^
   |
   = note: calls in constants are limited to constant functions, tuple structs and tuple variants
   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0010, E0015.
For more information about an error, try `rustc --explain E0010`.