src/tools/clippy/tests/ui/manual_async_fn.fixed

#![warn(clippy::manual_async_fn)]
#![allow(clippy::needless_pub_self, unused)]

use std::future::Future;

async fn fut() -> i32 { 42 }

#[rustfmt::skip]
async fn fut2() -> i32 { 42 }

#[rustfmt::skip]
async fn fut3() -> i32 { 42 }

async fn empty_fut() {}

#[rustfmt::skip]
async fn empty_fut2() {}

#[rustfmt::skip]
async fn empty_fut3() {}

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> + use<> {
    async { 42 }
}

#[allow(clippy::needless_lifetimes)]
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> + use<> {
    async { 42 }
}

// should be ignored
mod issue_5765 {
    use std::future::Future;

    struct A;
    impl A {
        fn f(&self) -> impl Future<Output = ()> + use<> {
            async {}
        }
    }

    fn test() {
        let _future = {
            let a = A;
            a.f()
        };
    }
}

pub async fn issue_10450() -> i32 { 42 }

pub(crate) async fn issue_10450_2() -> i32 { 42 }

pub(self) async fn issue_10450_3() -> i32 { 42 }

macro_rules! issue_12407 {
    (
        $(
            $(#[$m:meta])*
            $v:vis $(override($($overrides:tt),* $(,)?))? fn $name:ident $([$($params:tt)*])? (
                $($arg_name:ident: $arg_typ:ty),* $(,)?
            ) $(-> $ret_ty:ty)? = $e:expr;
        )*
    ) => {
        $(
            $(#[$m])*
            $v $($($overrides)*)? fn $name$(<$($params)*>)?(
                $($arg_name: $arg_typ),*
            ) $(-> $ret_ty)? {
                $e
            }
        )*
    };
}

issue_12407! {
    fn _hello() -> impl Future<Output = ()> = async {};
    fn non_async() = println!("hello");
    fn foo() = non_async();
}

fn main() {}