"unzip" a vector of Pairs

question

#1

Given a Vector of Pairs, what’s an idiomatic way of getting a vector of first and second elements in each Pair? MWE:

x = [Pair(x,2*x) for x in 1:5]

then

julia>  collect.(collect(zip(((a,b) for (a,b) in x)...)))  # works, but convoluted
2-element Array{Array{Int64,1},1}:
 [1,2,3,4,5] 
 [2,4,6,8,10]

#3

first.(x) and last.(x) works pretty well and is terse.


#4

One possibility is

julia> [first(p) for p in x]
5-element Array{Int64,1}:
 1
 2
 3
 4
 5

julia> [last(p) for p in x]
5-element Array{Int64,1}:
  2
  4
  6
  8
 10

EDIT:
Which can be written as map(first, x) and map(last, x)

I do agree that it is counterintuitive / unfortunate that two loops through are required.