I am trying to define a closure which mutates its argument, without luck. Is there a way to define a closure which is mutating? Here’s an example of what I’m trying to achieve:

Thanks!

```
function a!(x)
for i = 1:size(x,1)
x[i] = 2.0 * x[i]
end
y = 1.0
return x
end
function a!(x,y)
for i = 1:size(x,1)
x[i] = 2.0 * x[i]
end
y = [1.0]
return x
end
function main()
x = [1.0]
y = [1.0]
# one argument
println("one argument")
println("x before function", x)
a!(x)
println("x after function", x)
f! = x -> a!(x)
println("x before closure", x)
f!(x)
println("x after closure", x)
# two arguments
println("two arguments")
println("x before function", x)
a!(x,y)
println("x after function", x)
g! = x -> a!(x,y) #### THIS IS WHAT DOES NOT WORK.
println("x before closure", x)
g!(x,y)
println("x after closure", x)
end
main()
```