Methods with unnamed arguments do not re-evaluate

[mossr]

When we define a method with unnamed arguments like this

f(::Example) = 100

if the Example structure is modified, the cell defining f(::Example) does not re-evaluate.

Yet, if we define the method like this

f(var::Example) = 100

it works properly and this cell will update when Example is modified.

(Also, I have to say, using Pluto for teaching has been incredible—amazing work with this package 💕)

[mossr]

Here's the example notebook I've been using to test this:

### A Pluto.jl notebook ###
# v0.11.14

using Markdown
using InteractiveUtils

# ╔═╡ 49189bb0-f61f-11ea-0310-6dcf4f48a544
mutable struct Example end

# ╔═╡ 5182ff1e-f61f-11ea-0643-a953c85169d9
f(::Example) = 100

# ╔═╡ 657580c0-f61f-11ea-39fc-8527b48b1c27
f(Example())

# ╔═╡ Cell order:
# ╠═49189bb0-f61f-11ea-0310-6dcf4f48a544
# ╠═5182ff1e-f61f-11ea-0643-a953c85169d9
# ╠═657580c0-f61f-11ea-39fc-8527b48b1c27

I simply modify the first cell which results in the last cell throwing a MethodError.