    {-# LANGUAGE PackageImports #-}
    {-# LANGUAGE CPP #-}

    module Data.Either
    (
      module Export,
    #if MIN_VERSION_base(4,7,0)
    #else
      isRight,
      isLeft,
    #endif
    )
    where

    import "base" Data.Either as Export

    #if MIN_VERSION_base(4,7,0)
    #else
    isRight :: Either a b -> Bool
    isRight (Right _) = True
    isRight _ = False

    isLeft :: Either a b -> Bool
    isLeft = not . isRight
    #endif