mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-01 00:49:30 +00:00
468 lines
15 KiB
Rust
468 lines
15 KiB
Rust
#![feature(plugin)]
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#![plugin(clippy)]
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#![deny(clippy, clippy_pedantic)]
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#![allow(blacklisted_name, unused, print_stdout, non_ascii_literal, new_without_default)]
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use std::collections::BTreeMap;
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use std::collections::HashMap;
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use std::ops::Mul;
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struct T;
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impl T {
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fn add(self, other: T) -> T { self } //~ERROR defining a method called `add`
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fn drop(&mut self) { } //~ERROR defining a method called `drop`
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fn sub(&self, other: T) -> &T { self } // no error, self is a ref
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fn div(self) -> T { self } // no error, different #arguments
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fn rem(self, other: T) { } // no error, wrong return type
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fn into_u32(self) -> u32 { 0 } // fine
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fn into_u16(&self) -> u16 { 0 } //~ERROR methods called `into_*` usually take self by value
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fn to_something(self) -> u32 { 0 } //~ERROR methods called `to_*` usually take self by reference
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fn new(self) {}
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//~^ ERROR methods called `new` usually take no self
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//~| ERROR methods called `new` usually return `Self`
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}
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struct Lt<'a> {
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foo: &'a u32,
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}
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impl<'a> Lt<'a> {
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// The lifetime is different, but that’s irrelevant, see #734
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#[allow(needless_lifetimes)]
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pub fn new<'b>(s: &'b str) -> Lt<'b> { unimplemented!() }
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}
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struct Lt2<'a> {
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foo: &'a u32,
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}
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impl<'a> Lt2<'a> {
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// The lifetime is different, but that’s irrelevant, see #734
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pub fn new(s: &str) -> Lt2 { unimplemented!() }
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}
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#[derive(Clone,Copy)]
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struct U;
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impl U {
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fn new() -> Self { U }
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fn to_something(self) -> u32 { 0 } // ok because U is Copy
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}
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struct V<T> {
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_dummy: T
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}
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impl<T> V<T> {
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fn new() -> Option<V<T>> { None }
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}
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impl Mul<T> for T {
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type Output = T;
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fn mul(self, other: T) -> T { self } // no error, obviously
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}
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/// Utility macro to test linting behavior in `option_methods()`
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/// The lints included in `option_methods()` should not lint if the call to map is partially
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/// within a macro
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macro_rules! opt_map {
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($opt:expr, $map:expr) => {($opt).map($map)};
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}
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/// Checks implementation of the following lints:
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/// OPTION_MAP_UNWRAP_OR
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/// OPTION_MAP_UNWRAP_OR_ELSE
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fn option_methods() {
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let opt = Some(1);
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// Check OPTION_MAP_UNWRAP_OR
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// single line case
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let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or(a)`
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//~| NOTE replace `map(|x| x + 1).unwrap_or(0)`
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.unwrap_or(0); // should lint even though this call is on a separate line
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// multi line cases
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let _ = opt.map(|x| { //~ ERROR called `map(f).unwrap_or(a)`
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x + 1
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}
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).unwrap_or(0);
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let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or(a)`
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.unwrap_or({
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0
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});
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// macro case
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let _ = opt_map!(opt, |x| x + 1).unwrap_or(0); // should not lint
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// Check OPTION_MAP_UNWRAP_OR_ELSE
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// single line case
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let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or_else(g)`
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//~| NOTE replace `map(|x| x + 1).unwrap_or_else(|| 0)`
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.unwrap_or_else(|| 0); // should lint even though this call is on a separate line
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// multi line cases
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let _ = opt.map(|x| { //~ ERROR called `map(f).unwrap_or_else(g)`
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x + 1
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}
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).unwrap_or_else(|| 0);
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let _ = opt.map(|x| x + 1) //~ ERROR called `map(f).unwrap_or_else(g)`
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.unwrap_or_else(||
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0
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);
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// macro case
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let _ = opt_map!(opt, |x| x + 1).unwrap_or_else(|| 0); // should not lint
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}
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/// Struct to generate false positive for Iterator-based lints
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#[derive(Copy, Clone)]
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struct IteratorFalsePositives {
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foo: u32,
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}
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impl IteratorFalsePositives {
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fn filter(self) -> IteratorFalsePositives {
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self
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}
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fn next(self) -> IteratorFalsePositives {
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self
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}
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fn find(self) -> Option<u32> {
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Some(self.foo)
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}
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fn position(self) -> Option<u32> {
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Some(self.foo)
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}
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fn rposition(self) -> Option<u32> {
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Some(self.foo)
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}
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}
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/// Checks implementation of FILTER_NEXT lint
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fn filter_next() {
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let v = vec![3, 2, 1, 0, -1, -2, -3];
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// check single-line case
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let _ = v.iter().filter(|&x| *x < 0).next();
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//~^ ERROR called `filter(p).next()` on an Iterator.
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//~| NOTE replace `filter(|&x| *x < 0).next()`
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// check multi-line case
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let _ = v.iter().filter(|&x| { //~ERROR called `filter(p).next()` on an Iterator.
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*x < 0
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}
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).next();
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// check that we don't lint if the caller is not an Iterator
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let foo = IteratorFalsePositives { foo: 0 };
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let _ = foo.filter().next();
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}
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/// Checks implementation of SEARCH_IS_SOME lint
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fn search_is_some() {
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let v = vec![3, 2, 1, 0, -1, -2, -3];
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// check `find().is_some()`, single-line
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let _ = v.iter().find(|&x| *x < 0).is_some();
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//~^ ERROR called `is_some()` after searching
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//~| NOTE replace `find(|&x| *x < 0).is_some()`
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// check `find().is_some()`, multi-line
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let _ = v.iter().find(|&x| { //~ERROR called `is_some()` after searching
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*x < 0
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}
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).is_some();
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// check `position().is_some()`, single-line
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let _ = v.iter().position(|&x| x < 0).is_some();
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//~^ ERROR called `is_some()` after searching
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//~| NOTE replace `position(|&x| x < 0).is_some()`
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// check `position().is_some()`, multi-line
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let _ = v.iter().position(|&x| { //~ERROR called `is_some()` after searching
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x < 0
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}
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).is_some();
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// check `rposition().is_some()`, single-line
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let _ = v.iter().rposition(|&x| x < 0).is_some();
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//~^ ERROR called `is_some()` after searching
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//~| NOTE replace `rposition(|&x| x < 0).is_some()`
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// check `rposition().is_some()`, multi-line
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let _ = v.iter().rposition(|&x| { //~ERROR called `is_some()` after searching
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x < 0
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}
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).is_some();
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// check that we don't lint if the caller is not an Iterator
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let foo = IteratorFalsePositives { foo: 0 };
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let _ = foo.find().is_some();
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let _ = foo.position().is_some();
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let _ = foo.rposition().is_some();
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}
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/// Checks implementation of the OR_FUN_CALL lint
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fn or_fun_call() {
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struct Foo;
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impl Foo {
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fn new() -> Foo { Foo }
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}
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fn make<T>() -> T { unimplemented!(); }
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let with_constructor = Some(vec![1]);
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with_constructor.unwrap_or(make());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_constructor.unwrap_or_else(make)
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let with_new = Some(vec![1]);
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with_new.unwrap_or(Vec::new());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_new.unwrap_or_default();
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let with_const_args = Some(vec![1]);
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with_const_args.unwrap_or(Vec::with_capacity(12));
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_const_args.unwrap_or_else(|| Vec::with_capacity(12));
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let with_err : Result<_, ()> = Ok(vec![1]);
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with_err.unwrap_or(make());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_err.unwrap_or_else(|_| make());
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let with_err_args : Result<_, ()> = Ok(vec![1]);
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with_err_args.unwrap_or(Vec::with_capacity(12));
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_err_args.unwrap_or_else(|_| Vec::with_capacity(12));
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let with_default_trait = Some(1);
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with_default_trait.unwrap_or(Default::default());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_default_trait.unwrap_or_default();
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let with_default_type = Some(1);
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with_default_type.unwrap_or(u64::default());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_default_type.unwrap_or_default();
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let with_vec = Some(vec![1]);
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with_vec.unwrap_or(vec![]);
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION with_vec.unwrap_or_else(|| vec![]);
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let without_default = Some(Foo);
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without_default.unwrap_or(Foo::new());
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//~^ERROR use of `unwrap_or`
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//~|HELP try this
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//~|SUGGESTION without_default.unwrap_or_else(Foo::new);
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let mut map = HashMap::<u64, String>::new();
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map.entry(42).or_insert(String::new());
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//~^ERROR use of `or_insert` followed by a function call
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//~|HELP try this
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//~|SUGGESTION map.entry(42).or_insert_with(String::new);
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let mut btree = BTreeMap::<u64, String>::new();
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btree.entry(42).or_insert(String::new());
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//~^ERROR use of `or_insert` followed by a function call
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//~|HELP try this
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//~|SUGGESTION btree.entry(42).or_insert_with(String::new);
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}
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fn main() {
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use std::io;
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let opt = Some(0);
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let _ = opt.unwrap(); //~ERROR used unwrap() on an Option
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let res: Result<i32, ()> = Ok(0);
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let _ = res.unwrap(); //~ERROR used unwrap() on a Result
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let _ = "str".to_string(); //~ERROR `"str".to_owned()` is faster
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let v = &"str";
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let string = v.to_string(); //~ERROR `(*v).to_owned()` is faster
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let _again = string.to_string(); //~ERROR `String::to_string` is an inefficient way to clone a `String`; use `clone()` instead
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res.ok().expect("disaster!"); //~ERROR called `ok().expect()`
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// the following should not warn, since `expect` isn't implemented unless
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// the error type implements `Debug`
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let res2: Result<i32, MyError> = Ok(0);
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res2.ok().expect("oh noes!");
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let res3: Result<u32, MyErrorWithParam<u8>>= Ok(0);
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res3.ok().expect("whoof"); //~ERROR called `ok().expect()`
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let res4: Result<u32, io::Error> = Ok(0);
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res4.ok().expect("argh"); //~ERROR called `ok().expect()`
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let res5: io::Result<u32> = Ok(0);
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res5.ok().expect("oops"); //~ERROR called `ok().expect()`
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let res6: Result<u32, &str> = Ok(0);
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res6.ok().expect("meh"); //~ERROR called `ok().expect()`
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}
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struct MyError(()); // doesn't implement Debug
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#[derive(Debug)]
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struct MyErrorWithParam<T> {
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x: T
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}
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fn starts_with() {
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"".chars().next() == Some(' ');
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//~^ ERROR starts_with
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//~| HELP like this
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//~| SUGGESTION "".starts_with(' ')
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Some(' ') != "".chars().next();
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//~^ ERROR starts_with
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//~| HELP like this
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//~| SUGGESTION !"".starts_with(' ')
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}
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fn use_extend_from_slice() {
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let mut v : Vec<&'static str> = vec![];
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v.extend(&["Hello", "World"]); //~ERROR use of `extend`
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v.extend(&vec!["Some", "more"]);
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//~^ERROR use of `extend`
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//~| HELP try this
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//~| SUGGESTION v.extend_from_slice(&vec!["Some", "more"]);
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v.extend(vec!["And", "even", "more"].iter()); //~ERROR use of `extend`
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let o : Option<&'static str> = None;
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v.extend(o);
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v.extend(Some("Bye"));
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v.extend(vec!["Not", "like", "this"]);
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v.extend(["But", "this"].iter());
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//~^ERROR use of `extend
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//~| HELP try this
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//~| SUGGESTION v.extend_from_slice(&["But", "this"]);
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}
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fn clone_on_copy() {
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42.clone(); //~ERROR using `clone` on a `Copy` type
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vec![1].clone(); // ok, not a Copy type
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Some(vec![1]).clone(); // ok, not a Copy type
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}
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fn clone_on_copy_generic<T: Copy>(t: T) {
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t.clone(); //~ERROR using `clone` on a `Copy` type
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Some(t).clone(); //~ERROR using `clone` on a `Copy` type
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}
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fn clone_on_double_ref() {
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let x = vec![1];
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let y = &&x;
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let z: &Vec<_> = y.clone(); //~ERROR using `clone` on a double
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//~| HELP try dereferencing it
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//~| SUGGESTION let z: &Vec<_> = (*y).clone();
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//~^^^ERROR using `clone` on a `Copy` type
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println!("{:p} {:p}",*y, z);
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}
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fn single_char_pattern() {
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let x = "foo";
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x.split("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.split('x');
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x.split("xx");
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x.split('x');
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let y = "x";
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x.split(y);
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// Not yet testing for multi-byte characters
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// Changing `r.len() == 1` to `r.chars().count() == 1` in `lint_single_char_pattern`
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// should have done this but produced an ICE
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//
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// We may not want to suggest changing these anyway
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// See: https://github.com/Manishearth/rust-clippy/issues/650#issuecomment-184328984
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x.split("ß");
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x.split("ℝ");
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x.split("💣");
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// Can't use this lint for unicode code points which don't fit in a char
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x.split("❤️");
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x.contains("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.contains('x');
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x.starts_with("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.starts_with('x');
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x.ends_with("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.ends_with('x');
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x.find("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.find('x');
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x.rfind("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rfind('x');
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x.rsplit("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rsplit('x');
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x.split_terminator("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.split_terminator('x');
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x.rsplit_terminator("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rsplit_terminator('x');
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x.splitn(0, "x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.splitn(0, 'x');
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x.rsplitn(0, "x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rsplitn(0, 'x');
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x.matches("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.matches('x');
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x.rmatches("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rmatches('x');
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x.match_indices("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.match_indices('x');
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x.rmatch_indices("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.rmatch_indices('x');
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x.trim_left_matches("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.trim_left_matches('x');
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x.trim_right_matches("x");
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//~^ ERROR single-character string constant used as pattern
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//~| HELP try using a char instead:
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//~| SUGGESTION x.trim_right_matches('x');
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}
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