rust/tests/ui/auto-traits/suspicious-impls-lint.rs

#![deny(suspicious_auto_trait_impls)]

use std::marker::PhantomData;

struct MayImplementSendOk<T>(T);
unsafe impl<T: Send> Send for MayImplementSendOk<T> {} // ok

struct MayImplementSendErr<T>(T);
unsafe impl<T: Send> Send for MayImplementSendErr<&T> {}
//~^ ERROR
//~| WARNING this will change its meaning

struct ContainsNonSendDirect<T>(*const T);
unsafe impl<T: Send> Send for ContainsNonSendDirect<&T> {} // ok

struct ContainsPtr<T>(*const T);
struct ContainsIndirectNonSend<T>(ContainsPtr<T>);
unsafe impl<T: Send> Send for ContainsIndirectNonSend<&T> {} // ok

struct ContainsVec<T>(Vec<T>);
unsafe impl Send for ContainsVec<i32> {}
//~^ ERROR
//~| WARNING this will change its meaning

struct TwoParams<T, U>(T, U);
unsafe impl<T: Send, U: Send> Send for TwoParams<T, U> {} // ok

struct TwoParamsFlipped<T, U>(T, U);
unsafe impl<T: Send, U: Send> Send for TwoParamsFlipped<U, T> {} // ok

struct TwoParamsSame<T, U>(T, U);
unsafe impl<T: Send> Send for TwoParamsSame<T, T> {}
//~^ ERROR
//~| WARNING this will change its meaning

pub struct WithPhantomDataNonSend<T, U>(PhantomData<*const T>, U);
unsafe impl<T> Send for WithPhantomDataNonSend<T, i8> {} // ok

pub struct WithPhantomDataSend<T, U>(PhantomData<T>, U);
unsafe impl<T> Send for WithPhantomDataSend<*const T, i8> {}
//~^ ERROR
//~| WARNING this will change its meaning

pub struct WithLifetime<'a, T>(&'a (), T);
unsafe impl<T> Send for WithLifetime<'static, T> {} // ok
unsafe impl<T> Sync for WithLifetime<'static, Vec<T>> {}
//~^ ERROR
//~| WARNING this will change its meaning

fn main() {}