error[E0277]: the trait bound `{integer}: Buy` is not satisfied
  --> src/main.rs:4:13
   |
2  |     buy(milk);
3  |     if they_have_eggs {
4  |         buy(6);
   |        
***
^ the trait `Buy` is not implemented for `{integer}`
   |         |
   |         required by a bound introduced by this call
   |
note: required by a bound in `buy`
  --> src/main.rs:11:22
   |
11 | fn buy(product: impl Buy) {
   |                      ^^^ required by this bound in `buy`

For more information about this error, try `rustc --explain E0277`.
error: could not compile `dad` (bin "errand") due to previous error