# Why can't we merge Missing and Nothing? **URL:** \ **Category:** Internals & Design\ **Created:** [June 28, 2019, 10:03am UTC](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793 "2019-06-28T10:03:59Z")\ **Posts on this page:** 1\ **Showing post:** 20

**Author:** ![HFriberg-mosek](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hfriberg-mosek/32/8376_2.png) [@HFriberg-mosek](https://discourse.julialang.org/u/HFriberg-mosek)\ **Post date:** [July 4, 2019, 2:02pm UTC](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793/20 "2019-07-04T14:02:19Z")

Since this thread is now a wall of text and many things were not said clearly enough, I made a monologue to summarize our discussion so far: [Me in post #1](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793): I get that `Nothing` and `Missing` serve different purposes, but can we somehow fulfill these difference usecases with just one type? [You in post #2](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793/2): No. [Me in post #7](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793/7): Ahh, I get it. The type is a behavioral contract. I accept the premise of two distinct types. [Me in post #9](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793/9): But can we then distill concrete guidelines for when exactly one should use one or the other type for a specific purpose? [Me in post #15](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793/15): The classic interpretation to use `Missing` when _has a value (but it is unknown)_ and `Nothing` when _has no value_ is definitely flawed for the listed reasons. Many good inputs to the discussion so far… --- _[View the full topic](https://discourse.julialang.org/t/why-cant-we-merge-missing-and-nothing/25793)._