example1.jl

using GPUArrays
# Overloading the Julia Base map! function for GPUArrays
function Base.map!(f::Function, A::GPUArray, B::GPUArray)
    # the below is the Julia syntax to create a closure and pass it
    # as the first argument to gpu_call
    gpu_call(A, (f, A, B)) do state, f, A, B
        # If launch parameters arent specified, linear_index gets the index
        # into the Array passed as second argument to gpu_call (`A`)
        i = linear_index(state)
        A[i] = f(B[i])
        return
    end
end