119 lines
2.2 KiB
Rust
119 lines
2.2 KiB
Rust
#![warn(clippy::unused_async)]
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#![allow(incomplete_features)]
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use std::future::Future;
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use std::pin::Pin;
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mod issue10800 {
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#![allow(dead_code, unused_must_use, clippy::no_effect)]
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use std::future::ready;
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async fn async_block_await() {
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//~^ ERROR: unused `async` for function with no await statements
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async {
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ready(()).await;
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};
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}
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async fn normal_block_await() {
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{
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{
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ready(()).await;
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}
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}
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}
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}
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mod issue10459 {
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trait HasAsyncMethod {
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async fn do_something() -> u32;
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}
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impl HasAsyncMethod for () {
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async fn do_something() -> u32 {
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1
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}
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}
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}
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mod issue9695 {
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use std::future::Future;
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async fn f() {}
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async fn f2() {}
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async fn f3() {}
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//~^ ERROR: unused `async` for function with no await statements
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fn needs_async_fn<F: Future<Output = ()>>(_: fn() -> F) {}
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fn test() {
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let x = f;
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needs_async_fn(x); // async needed in f
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needs_async_fn(f2); // async needed in f2
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f3(); // async not needed in f3
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}
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}
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mod issue13466 {
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use std::future::Future;
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struct Wrap<F>(F);
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impl<F> From<F> for Wrap<F> {
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fn from(f: F) -> Self {
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Self(f)
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}
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}
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fn takes_fut<F: Fn() -> Fut, Fut: Future>(_: Wrap<F>) {}
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async fn unused_async() {}
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fn fp() {
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takes_fut(unused_async.into());
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}
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}
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async fn foo() -> i32 {
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//~^ ERROR: unused `async` for function with no await statements
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4
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}
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async fn bar() -> i32 {
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foo().await
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}
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struct S;
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impl S {
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async fn unused(&self) -> i32 {
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//~^ ERROR: unused `async` for function with no await statements
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1
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}
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async fn used(&self) -> i32 {
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self.unused().await
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}
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}
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trait AsyncTrait {
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fn trait_method() -> Pin<Box<dyn Future<Output = i32>>>;
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}
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macro_rules! async_trait_impl {
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() => {
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impl AsyncTrait for S {
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fn trait_method() -> Pin<Box<dyn Future<Output = i32>>> {
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async fn unused() -> i32 {
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5
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}
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Box::pin(unused())
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}
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}
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};
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}
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async_trait_impl!();
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fn main() {
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foo();
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bar();
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}
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