rust-clippy/tests/ui/manual_async_fn.fixed
Eduardo Broto e336fe80d2 manual_async_fn: take input lifetimes into account
The anonymous future returned from an `async fn` captures all input
lifetimes. This was not being taken into account.

See https://github.com/rust-lang/rfcs/blob/master/text/2394-async_await.md#lifetime-capture-in-the-anonymous-future
2020-08-03 00:36:28 +02:00

99 lines
1.8 KiB
Rust

// run-rustfix
// edition:2018
#![warn(clippy::manual_async_fn)]
#![allow(unused)]
use std::future::Future;
async fn fut() -> i32 { 42 }
async fn empty_fut() {}
async fn core_fut() -> i32 { 42 }
// should be ignored
fn has_other_stmts() -> impl core::future::Future<Output = i32> {
let _ = 42;
async move { 42 }
}
// should be ignored
fn not_fut() -> i32 {
42
}
// should be ignored
async fn already_async() -> impl Future<Output = i32> {
async { 42 }
}
struct S {}
impl S {
async fn inh_fut() -> i32 {
// NOTE: this code is here just to check that the indentation is correct in the suggested fix
let a = 42;
let b = 21;
if a < b {
let c = 21;
let d = 42;
if c < d {
let _ = 42;
}
}
42
}
// should be ignored
fn not_fut(&self) -> i32 {
42
}
// should be ignored
fn has_other_stmts() -> impl core::future::Future<Output = i32> {
let _ = 42;
async move { 42 }
}
// should be ignored
async fn already_async(&self) -> impl Future<Output = i32> {
async { 42 }
}
}
// Tests related to lifetime capture
async fn elided(_: &i32) -> i32 { 42 }
// should be ignored
fn elided_not_bound(_: &i32) -> impl Future<Output = i32> {
async { 42 }
}
async fn explicit<'a, 'b>(_: &'a i32, _: &'b i32) -> i32 { 42 }
// should be ignored
#[allow(clippy::needless_lifetimes)]
fn explicit_not_bound<'a, 'b>(_: &'a i32, _: &'b i32) -> impl Future<Output = i32> {
async { 42 }
}
// should be ignored
mod issue_5765 {
use std::future::Future;
struct A;
impl A {
fn f(&self) -> impl Future<Output = ()> {
async {}
}
}
fn test() {
let _future = {
let a = A;
a.f()
};
}
}
fn main() {}