use crate::{How, IntoContext, IntoResultHow};

crate::seal!(pub(crate) private::Sealed);

pub trait Explain: Sealed {
    type Output;

    #[must_use]
    fn context(self, context: impl IntoContext) -> Self::Output;
}

impl<T, E> Sealed for Result<T, E> where Result<T, E>: IntoResultHow {}

impl<T, E> Explain for Result<T, E>
where
    Result<T, E>: IntoResultHow,
{
    type Output = Result<<Self as IntoResultHow>::T, How>;

    #[inline(always)]
    fn context(self, context: impl IntoContext) -> Self::Output {
        self.into_result_how().map_err(|e| e.context(context))
    }
}