Enum CloseReason 

pub enum CloseReason<'a> {
    Ended,
    Stale,
    Failed(&'a Error),
}

Why a connection ended.

Three, because three is what the code can tell apart. It deliberately does not include “the caller dropped it”: that would have to be reported from a Drop impl, and the module doc says why no hook is ever called from one.

Variants

Ended

The exchange finished it: the peer closed the connection after the response, or the response said Connection: close. Nothing went wrong — there is simply no second request to be had on it.

Stale

It was taken from the pool for a new request and turned out to have been closed by the peer while it sat idle.

The reason a request that did nothing wrong sometimes pays for a connect: this is the event that explains the Connected following it.

Failed(&'a Error)

It failed, and here is the failure.

Trait Implementations

impl<'a> Debug for CloseReason<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.