$ cargo run
   Compiling drop-example v0.1.0 (file:///projects/drop-example)
error[E0040]: explicit use of destructor method
  --> src/main.rs:16:7
   |
16 |     c.drop();
   |       ^^^^ explicit destructor calls not allowed
   |
help: consider using `drop` function
   |
16 -     c.drop();
16 +     drop(c);
   |

For more information about this error, try `rustc --explain E0040`.
error: could not compile `drop-example` (bin "drop-example") due to 1 previous error
