// Copyright 2020. The Tari Project
//
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//! Function which tries to convert a series of `T`s to `U`s.

use alloc::vec::Vec;
use core::convert::TryInto;

/// Tries to convert a series of `T`s to `U`s, returning an error at the first failure.
pub fn try_convert_all<T, U, I>(into_iter: I) -> Result<Vec<U>, T::Error>
where
    I: IntoIterator<Item = T>,
    T: TryInto<U>,
{
    let iter = into_iter.into_iter();
    let mut result = Vec::with_capacity(iter.size_hint().0);
    for item in iter {
        result.push(item.try_into()?);
    }
    Ok(result)
}

#[cfg(test)]
mod test {
    use super::*;

    #[test]
    fn convert_all() {
        let a: Vec<u32> = try_convert_all(vec![1i64, 2, 3, 4, 5]).unwrap();
        assert_eq!(a, [1, 2, 3, 4, 5]);
    }

    #[test]
    fn convert_all_failed() {
        assert!(try_convert_all::<_, u32, _>(vec![i64::MAX, 2, 3, 4, 5]).is_err());
    }
}
