Struct tower_util::error::optional::None

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pub struct None(_);

[−] Expand description

Error returned if the inner Service has not been set.

Trait Implementations

impl Debug for None[+]

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

Formats the value using the given formatter.

impl Display for None[+]

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

Formats the value using the given formatter.

impl Error for None[+]

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pub fn source(&self) -> Option<&(dyn Error + 'static)>[−]

The lower-level source of this error, if any.

pub fn backtrace(&self) -> Option<&Backtrace>[−]

🔬 This is a nightly-only experimental API. (backtrace)

Returns a stack backtrace, if available, of where this error occurred.

pub fn description(&self) -> &str[−]

👎 Deprecated since 1.42.0:

use the Display impl or to_string()

pub fn cause(&self) -> Option<&dyn Error>

👎 Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting