Trait FromEnvValue 

pub trait FromEnvValue: Sized {
    // Required method
    fn from_env_value(s: String) -> Result<Self, String>;
}

Trait for converting a raw env-var string into a typed value.

Implementations are provided for all FromStr types via a blanket impl. You can implement this trait for custom types that need special parsing.

Example

use dotenv::FromEnvValue;

let n = <u16 as FromEnvValue>::from_env_value("42".into()).unwrap();
assert_eq!(n, 42);

let b = <bool as FromEnvValue>::from_env_value("true".into()).unwrap();
assert!(b);

let err = <u16 as FromEnvValue>::from_env_value("abc".into()).unwrap_err();
assert!(!err.is_empty());

Required Methods

fn from_env_value(s: String) -> Result<Self, String>

Convert the raw string value into Self.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<T: FromStr> FromEnvValue for T

where T::Err: Display,