Fix behavior of complex

src/DynamicQuantities.jl

@@ -17,6 +17,7 @@ include("units.jl")
 include("constants.jl")
 include("uparse.jl")
 include("symbolic_dimensions.jl")
+include("complex.jl")
 include("disambiguities.jl")
 
 include("deprecated.jl")

src/complex.jl

@@ -0,0 +1,22 @@
+for (type, true_base_type, _) in ABSTRACT_QUANTITY_TYPES
+    base_type = true_base_type <: Number ? true_base_type : Number
+    @eval begin
+        function Base.complex(a::$type, b::$type)
+            a, b = promote_except_value(a, b)
+            dimension(a) == dimension(b) || throw(DimensionError(a, b))
+            return new_quantity(typeof(a), complex(ustrip(a), ustrip(b)), dimension(a))
+        end
+        function Base.complex(a::$type, b::$base_type)
+            iszero(dimension(a)) || throw(DimensionError(a, b))
+            return new_quantity(typeof(a), complex(ustrip(a), b), dimension(a))
+        end
+        function Base.complex(a::$base_type, b::$type)
+            iszero(dimension(b)) || throw(DimensionError(a, b))
+            return new_quantity(typeof(b), complex(a, ustrip(b)), dimension(b))
+        end
+    end
+    for (type2, _, _) in ABSTRACT_QUANTITY_TYPES
+        type == type2 && continue
+        @eval Base.complex(a::$type, b::$type2) = complex(promote_except_value(a, b)...)
+    end
+end

test/unittests.jl

@@ -19,6 +19,11 @@ function unsafe_isapprox(x, y; kwargs...)
     return isapprox(ustrip(x), ustrip(y); kwargs...) && dimension(x) == dimension(y)
 end
 
+# Just in case `runtests.jl` hasn't been run yet:
+@static if !hasmethod(round, Tuple{Int, SimpleRatio{Int}})
+    @eval Base.round(T, x::SimpleRatio) = round(T, x.num // x.den)
+end
+
 @testset "Basic utilities" begin
 
     for Q in [Quantity, GenericQuantity, RealQuantity], T in [DEFAULT_VALUE_TYPE, Float16, Float32, Float64], R in [DEFAULT_DIM_BASE_TYPE, Rational{Int16}, Rational{Int32}, SimpleRatio{Int}, SimpleRatio{SafeInt16}]
@@ -222,6 +227,33 @@ end
     @test ustrip(x) ≈ (1.0 + 0.5im) / 1000.0
     @test ulength(x) == -1.0
     @test utime(x) == 1.0
+
+    # Can also construct using `complex`
+    x = complex(1.0u"km/s", 0.5u"km/s")
+    @test typeof(x) === Quantity{Complex{Float64}, DEFAULT_DIM_TYPE}
+    @test x == (1.0 + 0.5im) * u"km/s"
+
+    x2 = complex(RealQuantity(1.0u"km/s"), RealQuantity(0.5u"km/s"))
+    @test typeof(x2) === Quantity{Complex{Float64}, DEFAULT_DIM_TYPE}
+    @test x2 == (1.0 + 0.5im) * u"km/s"
+
+    x3 = complex(RealQuantity(1.0u"km/s"), GenericQuantity(0.5u"km/s"))
+    @test typeof(x3) === GenericQuantity{Complex{Float64}, DEFAULT_DIM_TYPE}
+    @test x3 == (1.0 + 0.5im) * u"km/s"
+
+    # Or, construct from quantity and number
+    x4 = complex(Quantity(1.0), 0.5)
+    @test typeof(x4) === Quantity{Complex{Float64}, DEFAULT_DIM_TYPE}
+    @test x4 == (1.0 + 0.5im)
+
+    x5 = complex(1.0, Quantity(0.5))
+    @test typeof(x5) === Quantity{Complex{Float64}, DEFAULT_DIM_TYPE}
+    @test x5 == (1.0 + 0.5im)
+
+    # Error checking
+    @test_throws DimensionError complex(1.0u"km/s", 0.5u"m")
+    @test_throws DimensionError complex(1.0u"m", 0.5)
+    @test_throws DimensionError complex(1.0, 0.5u"m")
 end
 
 @testset "Fallbacks" begin