1 #![warn(clippy::option_map_unit_fn)]
4 fn do_nothing<T>(_: T) {}
6 fn diverge<T>(_: T) -> ! {
10 fn plus_one(value: usize) -> usize {
19 fn do_option_nothing(self: &Self, value: usize) {}
21 fn do_option_plus_one(self: &Self, value: usize) -> usize {
26 fn option_map_unit_fn() {
27 let x = HasOption { field: Some(10) };
29 x.field.map(plus_one);
30 let _ : Option<()> = x.field.map(do_nothing);
32 x.field.map(do_nothing);
34 x.field.map(do_nothing);
39 if let Some(value) = x.field { do_nothing(value + captured) };
40 let _ : Option<()> = x.field.map(|value| do_nothing(value + captured));
42 x.field.map(|value| x.do_option_nothing(value + captured));
44 x.field.map(|value| { x.do_option_plus_one(value + captured); });
47 x.field.map(|value| do_nothing(value + captured));
49 x.field.map(|value| { do_nothing(value + captured) });
51 x.field.map(|value| { do_nothing(value + captured); });
53 x.field.map(|value| { { do_nothing(value + captured); } });
56 x.field.map(|value| diverge(value + captured));
58 x.field.map(|value| { diverge(value + captured) });
60 x.field.map(|value| { diverge(value + captured); });
62 x.field.map(|value| { { diverge(value + captured); } });
65 x.field.map(|value| plus_one(value + captured));
66 x.field.map(|value| { plus_one(value + captured) });
67 x.field.map(|value| { let y = plus_one(value + captured); });
69 x.field.map(|value| { plus_one(value + captured); });
71 x.field.map(|value| { { plus_one(value + captured); } });
74 x.field.map(|ref value| { do_nothing(value + captured) });
77 x.field.map(|value| { do_nothing(value); do_nothing(value) });
79 x.field.map(|value| if value > 0 { do_nothing(value); do_nothing(value) });
81 // Suggestion for the let block should be `{ ... }` as it's too difficult to build a
82 // proper suggestion for these cases
87 x.field.map(|value| { do_nothing(value); do_nothing(value); });
89 // The following should suggest `if let Some(_X) ...` as it's difficult to generate a proper let variable name for them
90 Some(42).map(diverge);
91 "12".parse::<i32>().ok().map(diverge);
92 Some(plus_one(1)).map(do_nothing);
94 // Should suggest `if let Some(_y) ...` to not override the existing foo variable