Avoid GLOBAL_RNG where possible (#22)

Author: fingolfin

README.md

@@ -207,10 +207,10 @@ julia> rand(make(MVector{2,AbstractString}, String), SMatrix{3, 2})
  ["FMTKcBY8", "eoYtNntD"]  ["FzdD530L", "ux6sWGMU"]
  ["fFJuUtJQ", "H2mAQrIV"]  ["pt0OYFJw", "O0fCfjjR"]
 
-julia> Set(Iterators.take(Rand(RandomDevice(), 1:10), 3)) # RNG defaults to Random.GLOBAL_RNG
+julia> Set(Iterators.take(Rand(RandomDevice(), 1:10), 3)) # RNG defaults to Random.default_rng()
 Set([9, 2, 6]) # note that the set could end up with less than 3 elements if `Rand` generates duplicates
 
-julia> collect(Iterators.take(Uniform(1:10), 3)) # distributions can be iterated over, using Random.GLOBAL_RNG implicitly
+julia> collect(Iterators.take(Uniform(1:10), 3)) # distributions can be iterated over, using Random.default_rng() implicitly
 3-element Array{Int64,1}:
   7
  10

src/RandomExtensions.jl

@@ -9,14 +9,14 @@ export rand!, AbstractRNG, MersenneTwister, RandomDevice
 import Random: Sampler, rand, rand!, gentype
 
 using Random
-using Random: GLOBAL_RNG, SamplerTrivial, SamplerSimple, SamplerTag, SamplerType, Repetition
+using Random: SamplerTrivial, SamplerSimple, SamplerTag, SamplerType, Repetition
 
 using SparseArrays: sprand, sprandn, AbstractSparseArray, SparseVector, SparseMatrixCSC
 
 if isdefined(Random, :default_rng)
     using Random: default_rng
 else
-    @inline default_rng() = GLOBAL_RNG
+    @inline default_rng() = Random.GLOBAL_RNG
 end
 
 
@@ -60,7 +60,7 @@ include("macros.jl")
 ## updated rand docstring (TODO: replace Base's one)
 
 """
-    rand([rng=GLOBAL_RNG], [S], [C...]) # RandomExtensions
+    rand([rng=default_rng()], [S], [C...]) # RandomExtensions
 
 Pick a random element or collection of random elements from the set of values specified by `S`;
 `S` can be