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//@aux-build:proc_macros.rs
#![allow(clippy::unnecessary_fold, unused)]
#![warn(clippy::manual_try_fold)]
#![feature(try_trait_v2)]
//@no-rustfix
use std::ops::{ControlFlow, FromResidual, Try};
#[macro_use]
extern crate proc_macros;
// Test custom `Try` with more than 1 argument
struct NotOption(i32, i32);
impl<R> FromResidual<R> for NotOption {
fn from_residual(_: R) -> Self {
todo!()
}
}
impl Try for NotOption {
type Output = ();
type Residual = ();
fn from_output(_: Self::Output) -> Self {
todo!()
}
fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
todo!()
}
}
// Test custom `Try` with only 1 argument
#[derive(Default)]
struct NotOptionButWorse(i32);
impl<R> FromResidual<R> for NotOptionButWorse {
fn from_residual(_: R) -> Self {
todo!()
}
}
impl Try for NotOptionButWorse {
type Output = ();
type Residual = ();
fn from_output(_: Self::Output) -> Self {
todo!()
}
fn branch(self) -> ControlFlow<Self::Residual, Self::Output> {
todo!()
}
}
fn main() {
[1, 2, 3]
.iter()
.fold(Some(0i32), |sum, i| sum?.checked_add(*i))
//~^ manual_try_fold
.unwrap();
[1, 2, 3]
.iter()
.fold(NotOption(0i32, 0i32), |sum, i| NotOption(0i32, 0i32));
//~^ manual_try_fold
[1, 2, 3]
.iter()
.fold(NotOptionButWorse(0i32), |sum, i| NotOptionButWorse(0i32));
//~^ manual_try_fold
// Do not lint
[1, 2, 3].iter().try_fold(0i32, |sum, i| sum.checked_add(*i)).unwrap();
[1, 2, 3].iter().fold(0i32, |sum, i| sum + i);
[1, 2, 3]
.iter()
.fold(NotOptionButWorse::default(), |sum, i| NotOptionButWorse::default());
external! {
[1, 2, 3].iter().fold(Some(0i32), |sum, i| sum?.checked_add(*i)).unwrap();
[1, 2, 3].iter().try_fold(0i32, |sum, i| sum.checked_add(*i)).unwrap();
}
with_span! {
span
[1, 2, 3].iter().fold(Some(0i32), |sum, i| sum?.checked_add(*i)).unwrap();
[1, 2, 3].iter().try_fold(0i32, |sum, i| sum.checked_add(*i)).unwrap();
}
}
#[clippy::msrv = "1.26.0"]
fn msrv_too_low() {
[1, 2, 3]
.iter()
.fold(Some(0i32), |sum, i| sum?.checked_add(*i))
.unwrap();
}
#[clippy::msrv = "1.27.0"]
fn msrv_juust_right() {
[1, 2, 3]
.iter()
.fold(Some(0i32), |sum, i| sum?.checked_add(*i))
//~^ manual_try_fold
.unwrap();
}
mod issue11876 {
struct Foo;
impl Bar for Foo {
type Output = u32;
}
trait Bar: Sized {
type Output;
fn fold<A, F>(self, init: A, func: F) -> Fold<Self, A, F>
where
A: Clone,
F: Fn(A, Self::Output) -> A,
{
Fold { this: self, init, func }
}
}
#[allow(dead_code)]
struct Fold<S, A, F> {
this: S,
init: A,
func: F,
}
fn main() {
Foo.fold(Some(0), |acc, entry| Some(acc? + entry));
}
}
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