Add Base.zero and one

Author: MilesCranmer

src/utils.jl

@@ -45,6 +45,8 @@ Base.iterate(d::Dimensions) = (d, nothing)
 Base.iterate(::Dimensions, ::Nothing) = nothing
 Base.iterate(q::Quantity) = (q, nothing)
 Base.iterate(::Quantity, ::Nothing) = nothing
+Base.zero(::Type{Quantity{T}}) where {T} = Quantity(zero(T))
+Base.one(::Type{Quantity{T}}) where {T} = Quantity(one(T))
 
 Base.show(io::IO, d::Dimensions) =
     let tmp_io = IOBuffer()

test/unittests.jl

@@ -92,6 +92,11 @@ using Test
 
     @test abs(x) == Quantity(1.2, length=2 // 5)
     @test abs(x) == abs(Quantity(1.2, length=2 // 5))
+
+    @test one(Quantity{Float64}) == Quantity(1.0)
+    @test one(Quantity{String}) == Quantity("")
+    @test zero(Quantity{Float64}) == Quantity(0.0)
+    @test zero(Quantity{Int}) == Quantity(0, length=0, mass=0)
 end
 
 @testset "Fallbacks" begin