fn err_into<E>(self) -> ErrInto<Self, E>
    where
        Self: Sized,
        Self::Error: Into<E>,
    {
        assert_future::<Result<Self::Ok, E>, _>(ErrInto::new(self))
    }
/// Maps this future's [`Error`](TryFuture::Error) to a new error type
/// using the [`Into`](std::convert::Into) trait.
///
/// This method does for futures what the `?`-operator does for
/// [`Result`]: It lets the compiler infer the type of the resulting
/// error. Just as [`map_err`](TryFutureExt::map_err), this is useful for
/// example to ensure that futures have the same [`Error`](TryFuture::Error)
/// type when using [`select!`] or [`join!`].
///
/// Note that this method consumes the future it is called on and returns a
/// wrapped version of it.
///
/// # Examples
///
/// ```
/// use futures::future::TryFutureExt;
///
/// # futures::executor::block_on(async {
/// let future_err_u8 = async { Err::<(), u8>(1) };
/// let future_err_i32 = future_err_u8.err_into::<i32>();
/// # });
/// ```
///
/// [`join!`]: crate::join
/// [`select!`]: crate::select


This method does for futures what the `?`-operator does for
[`Result`]: It lets the compiler infer the type of the resulting
error.

Note that this method consumes the future it is called on and returns a
wrapped version of it.
This method does for futures what the ` ? ` - operator does for [ ` Result ` ] : It lets the compiler infer the type of the resulting error . Note that this method consumes the future it is called on and returns a wrapped version of it .
fn err_into<E>(self) -> ErrInto<Self, E>
    where
        Self: Sized,
        Self::Error: Into<E>,
    {
        assert_future::<Result<Self::Ok, E>, _>(ErrInto::new(self))
    }
fn err_into < E > ( self ) -> ErrInto < Self , E > where Self : Sized , Self :: Error : Into < E > , { assert_future :: < Result < Self :: Ok , E > , _ > ( ErrInto :: new ( self ) ) }
Maps this future's [`Error`](TryFuture::Error) to a new error type
using the [`Into`](std::convert::Into) trait.
Maps this future ' s [ ` Error ` ] ( TryFuture :: Error ) to a new error type using the [ ` Into ` ] ( std :: convert :: Into ) trait .
self
self
examples
```
use futures::future::TryFutureExt.
` ` ` use futures :: future :: TryFutureExt .
futures::executor::block_on(async {
None
});


[`join!`]: crate::join
[`select!`]: crate::select
[ ` join! ` ] : crate :: join [ ` select! ` ] : crate :: select