# Function type specification

**URL:** <https://discourse.julialang.org/t/function-type-specification/1749>\
**Category:** Internals & Design\
**Created:** [January 29, 2017, 5:37am UTC](https://discourse.julialang.org/t/function-type-specification/1749 "2017-01-29T05:37:18Z")\
**Posts on this page:** 1\
**Showing post:** 6

<div class="post-metadata">

**Author:** ![jameson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jameson/32/23_2.png) [@jameson](https://discourse.julialang.org/u/jameson)\
**Post date:** [January 31, 2017, 4:37pm UTC](https://discourse.julialang.org/t/function-type-specification/1749/6 "2017-01-31T16:37:41Z")

</div>

The biggest challenge right now to doing something like this is that the type of those functions isn’t `::Function(::Float64)::Float64`, they are `::Function(f, ::Float64)::Float64` and `::Function(g, ::Float64)::Float64`. For another recent post on the topic, see [Proposal for a first-class dispatch wrapper - #2 by jameson](https://discourse.julialang.org/t/proposal-for-a-first-class-dispatch-wrapper/1127/2).

---

_[View the full topic](https://discourse.julialang.org/t/function-type-specification/1749)._