| ### What it does | |
| Checks for usages of `Iterator::flat_map()` where `filter_map()` could be | |
| used instead. | |
| ### Why is this bad? | |
| When applicable, `filter_map()` is more clear since it shows that | |
| `Option` is used to produce 0 or 1 items. | |
| ### Example | |
| ``` | |
| let nums: Vec<i32> = ["1", "2", "whee!"].iter().flat_map(|x| x.parse().ok()).collect(); | |
| ``` | |
| Use instead: | |
| ``` | |
| let nums: Vec<i32> = ["1", "2", "whee!"].iter().filter_map(|x| x.parse().ok()).collect(); | |
| ``` |