Enum FromEnvError 

pub enum FromEnvError {
    Missing(String),
    Invalid {
        var: String,
        value: String,
        message: String,
    },
}

Error returned by FromEnv::from_env.

Example

let err = FromEnvError::missing("MY_VAR");
assert_eq!(err.to_string(), "environment variable `MY_VAR` is not set");

let err = FromEnvError::invalid("PORT", "abc", "invalid digit");
assert_eq!(
    err.to_string(),
    "environment variable `PORT` has invalid value `abc`: invalid digit"
);

Variants

Missing(String)

An environment variable was not set.

Invalid

An environment variable was set but could not be parsed.

Fields

var: String

The name of the environment variable.

value: String

The raw value of the environment variable.

message: String

A description of why parsing failed.

Implementations

impl FromEnvError

pub fn missing(var: impl Into<String>) -> Self

pub fn invalid( var: impl Into<String>, value: impl Into<String>, message: impl Into<String>, ) -> Self

Trait Implementations

impl Clone for FromEnvError

fn clone(&self) -> FromEnvError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FromEnvError

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

Formats the value using the given formatter.

impl Display for FromEnvError

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

Formats the value using the given formatter.

impl Error for FromEnvError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

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

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.