mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-21 02:23:19 +00:00
c3d58cd5fa
Fixes #13407
123 lines
3 KiB
Rust
123 lines
3 KiB
Rust
#![warn(clippy::if_then_some_else_none)]
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#![allow(clippy::redundant_pattern_matching, clippy::unnecessary_lazy_evaluations)]
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fn main() {
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// Should issue an error.
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let _ = foo().then(|| { println!("true!"); "foo" });
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// Should issue an error when macros are used.
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let _ = matches!(true, true).then(|| { println!("true!"); matches!(true, false) });
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// Should issue an error. Binary expression `o < 32` should be parenthesized.
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let x = Some(5);
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let _ = x.and_then(|o| (o < 32).then_some(o));
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//~^ ERROR: this could be simplified with `bool::then_some`
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// Should issue an error. Unary expression `!x` should be parenthesized.
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let x = true;
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let _ = (!x).then_some(0);
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//~^ ERROR: this could be simplified with `bool::then_some`
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// Should not issue an error since the `else` block has a statement besides `None`.
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let _ = if foo() {
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println!("true!");
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Some("foo")
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} else {
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eprintln!("false...");
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None
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};
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// Should not issue an error since there are more than 2 blocks in the if-else chain.
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let _ = if foo() {
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println!("foo true!");
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Some("foo")
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} else if bar() {
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println!("bar true!");
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Some("bar")
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} else {
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None
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};
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let _ = if foo() {
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println!("foo true!");
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Some("foo")
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} else {
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bar().then(|| {
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println!("bar true!");
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"bar"
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})
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};
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// Should not issue an error since the `then` block has `None`, not `Some`.
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let _ = if foo() { None } else { Some("foo is false") };
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// Should not issue an error since the `else` block doesn't use `None` directly.
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let _ = if foo() { Some("foo is true") } else { into_none() };
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// Should not issue an error since the `then` block doesn't use `Some` directly.
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let _ = if foo() { into_some("foo") } else { None };
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}
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#[clippy::msrv = "1.49"]
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fn _msrv_1_49() {
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// `bool::then` was stabilized in 1.50. Do not lint this
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let _ = if foo() {
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println!("true!");
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Some(149)
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} else {
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None
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};
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}
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#[clippy::msrv = "1.50"]
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fn _msrv_1_50() {
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let _ = foo().then(|| { println!("true!"); 150 });
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}
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fn foo() -> bool {
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unimplemented!()
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}
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fn bar() -> bool {
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unimplemented!()
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}
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fn into_some<T>(v: T) -> Option<T> {
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Some(v)
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}
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fn into_none<T>() -> Option<T> {
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None
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}
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// Should not warn
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fn f(b: bool, v: Option<()>) -> Option<()> {
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if b {
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v?; // This is a potential early return, is not equivalent with `bool::then`
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Some(())
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} else {
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None
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}
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}
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fn issue11394(b: bool, v: Result<(), ()>) -> Result<(), ()> {
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let x = if b {
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#[allow(clippy::let_unit_value)]
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let _ = v?;
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Some(())
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} else {
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None
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};
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Ok(())
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}
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fn issue13407(s: &str) -> Option<bool> {
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(s == "1").then(|| true)
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}
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const fn issue12103(x: u32) -> Option<u32> {
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// Should not issue an error in `const` context
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if x > 42 { Some(150) } else { None }
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}
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