Add ustrip() support to Base.TwicePrecision (#711)

Fixes #709

Author: staticfloat

src/range.jl

@@ -115,6 +115,7 @@ _colon(::Any, ::Any, start::T, step, stop::T) where {T} =
 *(x::Base.TwicePrecision, y::Units) = Base.TwicePrecision(x.hi*y, x.lo*y)
 *(x::Base.TwicePrecision, y::Quantity) = (x * ustrip(y)) * unit(y)
 uconvert(y, x::Base.TwicePrecision) = Base.TwicePrecision(uconvert(y, x.hi), uconvert(y, x.lo))
+ustrip(x::Base.TwicePrecision) = Base.TwicePrecision(ustrip(x.hi), ustrip(x.lo))
 @inline upreferred(x::Base.TwicePrecision{T}) where T<:Number = x
 @inline upreferred(x::Base.TwicePrecision{T}) where T<:AbstractQuantity =
     uconvert(upreferred(unit(x)), x)

test/runtests.jl

@@ -1400,6 +1400,10 @@ end
                 @test_throws ArgumentError range(step=1m, length=5)
             end
         end
+        @testset ">> broadcast ustrip" begin
+            @test ustrip.(1:0.1:1.0) == 1:0.1:1.0
+            @test ustrip.(1m:0.1m:1.0m) == 1:0.1:1.0
+        end
     end
     @testset "> Arrays" begin
         @testset ">> Array multiplication" begin