I was trying to implement a stack using an array for which I had to create a single value array `[nothing]`

. I needed `nothing`

because my code included peeking the array. But when I tried to push an integer value into the array it resulted in an error. Here is the code and the error:

```
julia> stack = [nothing]
1-element Array{Nothing,1}:
nothing
julia> push!(stack, 1)
ERROR: MethodError: convert(::Type{Union{}}, ::Int64) is ambiguous. Candidates:
convert(::Type{Union{}}, x) in Base at essentials.jl:169
convert(::Type{T}, x::Number) where T<:Number in Base at number.jl:7
convert(::Type{T}, arg) where T<:VecElement in Base at baseext.jl:8
convert(::Type{T}, x::Number) where T<:AbstractChar in Base at char.jl:179
Possible fix, define
convert(::Type{Union{}}, ::Number)
Stacktrace:
[1] convert(::Type{Nothing}, ::Int64) at ./some.jl:34
[2] push!(::Array{Nothing,1}, ::Int64) at ./array.jl:912
[3] top-level scope at REPL[11]:1
julia>
```

I want to use `nothing`

similar to `None`

in python. I am not sure if this is a bug or you canât use nothing in this way.