Struct EnvVariableName 

pub struct EnvVariableName(/* private fields */);

Validated environment variable name.

Ensures the name is non-empty and does not contain =.

Implementations

impl EnvVariableName

pub fn as_str(&self) -> &str

pub const fn from_static_or_panic(name: &'static str) -> Self

Validated environment variable name for 'static inputs.

Panics

Panics at compile time when used in a const context, or at runtime otherwise, if the name is empty or contains =.

pub fn read(&self) -> Result<EnvVariableValue, EnvVariableReadError>

Reads this variable from the current process environment.

Errors

Returns EnvVariableReadError when the variable is absent, holds a non-unicode value, or holds a value that fails EnvVariableValue validation.

pub fn is_present(&self) -> bool

Returns whether this variable is set in the current process environment.

Presence is independent of value validity: a value that would fail EnvVariableValue validation (non-unicode, oversized) still counts as present.

pub fn load_from_str<T>(&self) -> Result<T, EnvVariableLoadError<T::Err>>

where T: FromStr, T::Err: Error + 'static,

Reads this variable and parses its value via std::str::FromStr.

Errors

Returns EnvVariableLoadError::Read when the variable cannot be read (see EnvVariableName::read) or EnvVariableLoadError::Convert when parsing the value fails.

pub fn load_try_from<T>(&self) -> Result<T, EnvVariableLoadError<T::Error>>

where T: TryFrom<String>, T::Error: Error + 'static,

Reads this variable and converts its value via TryFrom<String>.

Errors

Returns EnvVariableLoadError::Read when the variable cannot be read (see EnvVariableName::read) or EnvVariableLoadError::Convert when the conversion fails.

Trait Implementations

impl AsRef<OsStr> for EnvVariableName

fn as_ref(&self) -> &OsStr

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for EnvVariableName

fn clone(&self) -> EnvVariableName

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EnvVariableName

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

Formats the value using the given formatter.

impl Display for EnvVariableName

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

Formats the value using the given formatter.

impl Eq for EnvVariableName

impl FromStr for EnvVariableName

type Err = EnvVariableNameError

The associated error which can be returned from parsing.

fn from_str(name: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Ord for EnvVariableName

fn cmp(&self, other: &EnvVariableName) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl PartialEq for EnvVariableName

fn eq(&self, other: &EnvVariableName) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for EnvVariableName

fn partial_cmp(&self, other: &EnvVariableName) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for EnvVariableName