error: a dangling pointer will be produced because the temporary `String` will be dropped
  --> $DIR/allow.rs:9:28
   |
LL |         dbg!(String::new().as_ptr());
   |              ------------- ^^^^^^ this pointer will immediately be invalid
   |              |
   |              this `String` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
   |
   = note: pointers do not have a lifetime; when calling `as_ptr` the `String` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
   = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
note: the lint level is defined here
  --> $DIR/allow.rs:7:12
   |
LL |     #[deny(dangling_pointers_from_temporaries)]
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: a dangling pointer will be produced because the temporary `String` will be dropped
  --> $DIR/allow.rs:20:28
   |
LL |         dbg!(String::new().as_ptr());
   |              ------------- ^^^^^^ this pointer will immediately be invalid
   |              |
   |              this `String` is deallocated at the end of the statement, bind it to a variable to extend its lifetime
   |
   = note: pointers do not have a lifetime; when calling `as_ptr` the `String` will be deallocated at the end of the statement because nothing is referencing it as far as the type system is concerned
   = help: for more information, see <https://doc.rust-lang.org/reference/destructors.html>
note: the lint level is defined here
  --> $DIR/allow.rs:18:12
   |
LL |     #[warn(dangling_pointers_from_temporaries)]
   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error: aborting due to 1 previous error; 1 warning emitted