1 #![feature(never_type)]
2 #![warn(clippy::result_map_unit_fn)]
5 fn do_nothing<T>(_: T) {}
7 fn diverge<T>(_: T) -> ! {
11 fn plus_one(value: usize) -> usize {
16 field: Result<usize, usize>,
20 fn do_result_nothing(self: &Self, value: usize) {}
22 fn do_result_plus_one(self: &Self, value: usize) -> usize {
28 fn result_map_unit_fn() {
29 let x = HasResult { field: Ok(10) };
31 x.field.map(plus_one);
32 let _: Result<(), usize> = x.field.map(do_nothing);
34 x.field.map(do_nothing);
36 x.field.map(do_nothing);
41 if let Ok(value) = x.field { do_nothing(value + captured) };
42 let _: Result<(), usize> = x.field.map(|value| do_nothing(value + captured));
44 x.field.map(|value| x.do_result_nothing(value + captured));
46 x.field.map(|value| { x.do_result_plus_one(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); });
55 x.field.map(|value| { { do_nothing(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); });
64 x.field.map(|value| { { diverge(value + captured); } });
67 x.field.map(|value| plus_one(value + captured));
68 x.field.map(|value| { plus_one(value + captured) });
69 x.field.map(|value| { let y = plus_one(value + captured); });
71 x.field.map(|value| { plus_one(value + captured); });
73 x.field.map(|value| { { plus_one(value + captured); } });
76 x.field.map(|ref value| { do_nothing(value + captured) });
79 x.field.map(|value| { do_nothing(value); do_nothing(value) });
81 x.field.map(|value| if value > 0 { do_nothing(value); do_nothing(value) });
83 // Suggestion for the let block should be `{ ... }` as it's too difficult to build a
84 // proper suggestion for these cases
89 x.field.map(|value| { do_nothing(value); do_nothing(value); });
91 // The following should suggest `if let Ok(_X) ...` as it's difficult to generate a proper let variable name for them
92 let res: Result<!, usize> = Ok(42).map(diverge);
93 "12".parse::<i32>().map(diverge);
95 let res: Result<(), usize> = Ok(plus_one(1)).map(do_nothing);
97 // Should suggest `if let Ok(_y) ...` to not override the existing foo variable
98 let y: Result<usize, usize> = Ok(42);