101 lines
2.5 KiB
Rust
101 lines
2.5 KiB
Rust
#![warn(option_map_unit_fn)]
|
|
#![allow(unused)]
|
|
|
|
fn do_nothing<T>(_: T) {}
|
|
|
|
fn diverge<T>(_: T) -> ! {
|
|
panic!()
|
|
}
|
|
|
|
fn plus_one(value: usize) -> usize {
|
|
value + 1
|
|
}
|
|
|
|
struct HasOption {
|
|
field: Option<usize>,
|
|
}
|
|
|
|
impl HasOption {
|
|
fn do_option_nothing(self: &Self, value: usize) {}
|
|
|
|
fn do_option_plus_one(self: &Self, value: usize) -> usize {
|
|
value + 1
|
|
}
|
|
}
|
|
|
|
fn option_map_unit_fn() {
|
|
let x = HasOption { field: Some(10) };
|
|
|
|
x.field.map(plus_one);
|
|
let _ : Option<()> = x.field.map(do_nothing);
|
|
|
|
x.field.map(do_nothing);
|
|
|
|
x.field.map(do_nothing);
|
|
|
|
x.field.map(diverge);
|
|
|
|
let captured = 10;
|
|
if let Some(value) = x.field { do_nothing(value + captured) };
|
|
let _ : Option<()> = x.field.map(|value| do_nothing(value + captured));
|
|
|
|
x.field.map(|value| x.do_option_nothing(value + captured));
|
|
|
|
x.field.map(|value| { x.do_option_plus_one(value + captured); });
|
|
|
|
|
|
x.field.map(|value| do_nothing(value + captured));
|
|
|
|
x.field.map(|value| { do_nothing(value + captured) });
|
|
|
|
x.field.map(|value| { do_nothing(value + captured); });
|
|
|
|
x.field.map(|value| { { do_nothing(value + captured); } });
|
|
|
|
|
|
x.field.map(|value| diverge(value + captured));
|
|
|
|
x.field.map(|value| { diverge(value + captured) });
|
|
|
|
x.field.map(|value| { diverge(value + captured); });
|
|
|
|
x.field.map(|value| { { diverge(value + captured); } });
|
|
|
|
|
|
x.field.map(|value| plus_one(value + captured));
|
|
x.field.map(|value| { plus_one(value + captured) });
|
|
x.field.map(|value| { let y = plus_one(value + captured); });
|
|
|
|
x.field.map(|value| { plus_one(value + captured); });
|
|
|
|
x.field.map(|value| { { plus_one(value + captured); } });
|
|
|
|
|
|
x.field.map(|ref value| { do_nothing(value + captured) });
|
|
|
|
|
|
x.field.map(|value| { do_nothing(value); do_nothing(value) });
|
|
|
|
x.field.map(|value| if value > 0 { do_nothing(value); do_nothing(value) });
|
|
|
|
// Suggestion for the let block should be `{ ... }` as it's too difficult to build a
|
|
// proper suggestion for these cases
|
|
x.field.map(|value| {
|
|
do_nothing(value);
|
|
do_nothing(value)
|
|
});
|
|
x.field.map(|value| { do_nothing(value); do_nothing(value); });
|
|
|
|
// The following should suggest `if let Some(_X) ...` as it's difficult to generate a proper let variable name for them
|
|
Some(42).map(diverge);
|
|
"12".parse::<i32>().ok().map(diverge);
|
|
Some(plus_one(1)).map(do_nothing);
|
|
|
|
// Should suggest `if let Some(_y) ...` to not override the existing foo variable
|
|
let y = Some(42);
|
|
y.map(do_nothing);
|
|
}
|
|
|
|
fn main() {
|
|
}
|