Support Float32/Float16 etc. type conversions (PainterQubits#296)

src/quantities.jl

@@ -383,13 +383,17 @@ function frexp(x::AbstractQuantity{T}) where {T <: AbstractFloat}
     a*unit(x), b
 end
 
-"""
-    float(x::AbstractQuantity)
-Convert the numeric backing type of `x` to a floating-point representation.
-Returns a `Quantity` with the same units.
-"""
-float(x::AbstractQuantity) = Quantity(float(x.val), unit(x))
-
+for f in (:float, :BigFloat, :Float64, :Float32, :Float16)
+    @eval begin
+    """
+        $($f)(x::AbstractQuantity)
+    Convert the numeric backing type of `x` to a floating-point representation.
+    Returns a `Quantity` with the same units.
+    """
+    (Base.$f)(x::AbstractQuantity) = Quantity($f(x.val), unit(x))
+    end
+end
+
 """
     Integer(x::AbstractQuantity)
 Convert the numeric backing type of `x` to an integer representation.

test/runtests.jl

@@ -130,6 +130,7 @@ end
     @testset "> Unitful ↔ unitful conversion" begin
         @testset ">> Numeric conversion" begin
             @test @inferred(float(3m)) === 3.0m
+            @test @inferred(Float32(3m)) === 3.0f0m
             @test @inferred(Integer(3.0A)) === 3A
             @test Rational(3.0m) === (Int64(3)//1)*m
             @test typeof(convert(typeof(0.0°), 90°)) == typeof(0.0°)