134 lines
3.1 KiB
Rust
134 lines
3.1 KiB
Rust
// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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#![warn(clippy::option_map_unit_fn)]
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#![allow(unused)]
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fn do_nothing<T>(_: T) {}
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fn diverge<T>(_: T) -> ! {
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panic!()
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}
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fn plus_one(value: usize) -> usize {
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value + 1
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}
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struct HasOption {
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field: Option<usize>,
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}
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impl HasOption {
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fn do_option_nothing(self: &Self, value: usize) {}
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fn do_option_plus_one(self: &Self, value: usize) -> usize {
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value + 1
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}
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}
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fn option_map_unit_fn() {
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let x = HasOption { field: Some(10) };
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x.field.map(plus_one);
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let _: Option<()> = x.field.map(do_nothing);
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x.field.map(do_nothing);
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x.field.map(do_nothing);
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x.field.map(diverge);
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let captured = 10;
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if let Some(value) = x.field {
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do_nothing(value + captured)
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};
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let _: Option<()> = x.field.map(|value| do_nothing(value + captured));
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x.field.map(|value| x.do_option_nothing(value + captured));
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x.field.map(|value| {
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x.do_option_plus_one(value + captured);
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});
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x.field.map(|value| do_nothing(value + captured));
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x.field.map(|value| do_nothing(value + captured));
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x.field.map(|value| {
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do_nothing(value + captured);
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});
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x.field.map(|value| {
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do_nothing(value + captured);
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});
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x.field.map(|value| diverge(value + captured));
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x.field.map(|value| diverge(value + captured));
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x.field.map(|value| {
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diverge(value + captured);
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});
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x.field.map(|value| {
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diverge(value + captured);
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});
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x.field.map(|value| plus_one(value + captured));
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x.field.map(|value| plus_one(value + captured));
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x.field.map(|value| {
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let y = plus_one(value + captured);
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});
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x.field.map(|value| {
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plus_one(value + captured);
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});
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x.field.map(|value| {
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plus_one(value + captured);
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});
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x.field.map(|ref value| do_nothing(value + captured));
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x.field.map(|value| {
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do_nothing(value);
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do_nothing(value)
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});
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x.field.map(|value| {
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if value > 0 {
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do_nothing(value);
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do_nothing(value)
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}
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});
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// Suggestion for the let block should be `{ ... }` as it's too difficult to build a
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// proper suggestion for these cases
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x.field.map(|value| {
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do_nothing(value);
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do_nothing(value)
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});
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x.field.map(|value| {
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do_nothing(value);
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do_nothing(value);
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});
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// The following should suggest `if let Some(_X) ...` as it's difficult to generate a proper let
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// variable name for them
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Some(42).map(diverge);
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"12".parse::<i32>().ok().map(diverge);
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Some(plus_one(1)).map(do_nothing);
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// Should suggest `if let Some(_y) ...` to not override the existing foo variable
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let y = Some(42);
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y.map(do_nothing);
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}
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fn main() {}
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