rust/tests/ui/option_map_unit_fn.rs

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2018-04-09 06:20:46 +00:00
#![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
}
}
#[cfg_attr(rustfmt, rustfmt_skip)]
fn main() {
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); });
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}