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#![cfg_attr(feature = "no_std", no_std)]
#[macro_use]
extern crate cfg_if;
cfg_if! (
if #[cfg(feature="no_std")] {
use core::str::FromStr;
} else {
use std::str::FromStr;
}
);
mod char;
mod int;
pub use char::TryFromIntToCharError;
pub use int::TryFromIntError;
pub trait TryFrom<T>: Sized {
type Err;
fn try_from(T) -> Result<Self, Self::Err>;
}
pub trait TryInto<T>: Sized {
type Err;
fn try_into(self) -> Result<T, Self::Err>;
}
impl<T, U> TryInto<U> for T
where
U: TryFrom<T>,
{
type Err = U::Err;
fn try_into(self) -> Result<U, U::Err> {
U::try_from(self)
}
}
impl<'a, T> TryFrom<&'a str> for T
where
T: FromStr,
{
type Err = T::Err;
fn try_from(string: &'a str) -> Result<Self, Self::Err> {
T::from_str(string)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn should_have_try_from_impl_for_from_str() {
let result = u32::try_from("3");
assert_eq!(result.unwrap(), 3)
}
#[test]
fn should_have_try_from_impl_for_from_str_that_handles_err() {
let result = u32::try_from("hello");
assert_eq!(
format!("{}", result.unwrap_err()),
"invalid digit found in string"
)
}
#[test]
fn should_have_try_into_impl_for_from_str() {
let result: Result<u32, _> = "3".try_into();
assert_eq!(result.unwrap(), 3)
}
}
#[derive(Debug, Eq, PartialEq)]
pub enum Void {}