//! Tuple traits
use super::*;

pub trait TryUntupleTwoExt<T,U>: Sized
{
    type Wrapper<S>;
    fn both(self) -> Self::Wrapper<(T, U)>;
}

impl<T, U> TryUntupleTwoExt<T, U> for (T, Option<U>)
{
    type Wrapper<S> = Option<S>;
    #[inline] 
    fn both(self) -> Self::Wrapper<(T, U)> {
	match self {
	    (first, Some(second)) => Some((first, second)),
	    _ => None,
	}
    }
}

impl<T, U> TryUntupleTwoExt<T, U> for (Option<T>, U)
{
    type Wrapper<S> = Option<S>;
    #[inline] 
    fn both(self) -> Self::Wrapper<(T, U)> {
	match self {
	    (Some(first), second) => Some((first, second)),
	    _ => None,
	}
    }
}

impl<T, U> TryUntupleTwoExt<T, U> for (Option<T>, Option<U>)
{
    type Wrapper<S> = Option<S>;
    #[inline] 
    fn both(self) -> Self::Wrapper<(T, U)> {
	match self {
	    (Some(first), Some(second)) => Some((first, second)),
	    _ => None,
	}
    }
}

pub trait UntupleTwoExt<T,U,V>: Sized
{
    type Unwrapped<A,B,C>;
    
    fn untuple(self) -> Self::Unwrapped<T,U,V>;
}

impl<T, U, V> UntupleTwoExt<T,U,V> for (T, (U, V))
{
    type Unwrapped<A,B,C> = (A,B,C);
    #[inline] 
    fn untuple(self) -> Self::Unwrapped<T,U,V> {
	(self.0, self.1.0, self.1.1)
    }
}

impl<T, U> UntupleTwoExt<T,U,()> for (T, (U,))
{
    type Unwrapped<A,B,C> = (A,B);
    #[inline] 
    fn untuple(self) -> Self::Unwrapped<T,U,()> {
	(self.0, self.1.0)
    }
}

impl<T> UntupleTwoExt<T,(),()> for (T,)
{
    type Unwrapped<A,B,C> = A;
    #[inline] 
    fn untuple(self) -> Self::Unwrapped<T,(),()> {
	self.0
    }
}