Fix complex constructors

Add some tests

src/fixed.jl

@@ -8,8 +8,8 @@ struct Fixed{T <: Signed,f} <: FixedPoint{T,  f}
     Fixed{T, f}(x) where {T,f} = convert(Fixed{T,f}, x)
     Fixed{T, f}(x::Fixed{T,f}) where {T,f} = x
     Fixed{T, f}(x::Char) where {T,f} = throw(ArgumentError("Fixed cannot be constructed from a Char"))
-    Fixed{T, f}(x::Complex) where {T,f} = Fixed{T, f}(real(x))
-    Fixed{T, f}(x::Base.TwicePrecision) where {T,f,S} = Fixed{T, f}(convert(Float64, x))
+    Fixed{T, f}(x::Complex) where {T,f} = Fixed{T, f}(convert(real(typeof(x)), x))
+    Fixed{T, f}(x::Base.TwicePrecision) where {T,f} = Fixed{T, f}(convert(Float64, x))
 end
 
 reinterpret(::Type{Fixed{T,f}}, x::T) where {T <: Signed,f} = Fixed{T,f}(x, 0)

src/normed.jl

@@ -8,8 +8,8 @@ struct Normed{T<:Unsigned,f} <: FixedPoint{T,f}
     Normed{T, f}(x) where {T,f} = convert(Normed{T,f}, x)
     Normed{T, f}(x::Normed{T,f}) where {T,f} = x
     Normed{T, f}(x::Char) where {T,f} = throw(ArgumentError("Normed cannot be constructed from a Char"))
-    Normed{T, f}(x::Complex) where {T,f} = Normed{T, f}(real(x))
-    Normed{T, f}(x::Base.TwicePrecision) where {T,f,S} = Normed{T, f}(convert(Float64, x))
+    Normed{T, f}(x::Complex) where {T,f} = Normed{T, f}(convert(real(typeof(x)), x))
+    Normed{T, f}(x::Base.TwicePrecision) where {T,f} = Normed{T, f}(convert(Float64, x))
 end
 
 typechar(::Type{X}) where {X <: Normed} = 'N'

test/fixed.jl

@@ -1,4 +1,4 @@
-using FixedPointNumbers, Compat, Test
+using FixedPointNumbers, Compat.Test
 
 function test_op(fun::F, ::Type{T}, fx, fy, fxf, fyf, tol) where {F,T}
     # Make sure that the result is representable
@@ -129,3 +129,9 @@ end
 
 # issue #79
 @test realmin(Q11f4) == Q11f4(0.06)
+
+# Test disambiguation constructors
+@test_throws ArgumentError Fixed{Int32,16}('a')
+@test_throws InexactError  Fixed{Int32,16}(complex(1.0, 1.0))
+@test Fixed{Int32,16}(complex(1.0, 0.0))        == 1
+@test Fixed{Int32,16}(Base.TwicePrecision(1.0)) == 1

test/normed.jl

@@ -1,4 +1,4 @@
-using FixedPointNumbers, Compat, Test
+using FixedPointNumbers, Compat.Test
 
 @test reinterpret(N0f8, 0xa2).i  === 0xa2
 @test reinterpret(N6f10, 0x1fa2).i === 0x1fa2
@@ -313,3 +313,10 @@ elseif VERSION >= v"0.7.0-DEV.1790"
     @test summary(a) == "2-element Array{N0f8,1} with eltype FixedPointNumbers.Normed{UInt8,8}"
     @test summary(view(a, 1:2)) == "2-element view(::Array{N0f8,1}, 1:2) with eltype FixedPointNumbers.Normed{UInt8,8}"
 end
+
+# Test disambiguation constructors
+@test_throws ArgumentError Normed{UInt32,16}('a')
+@test_throws InexactError  Normed{UInt32,16}(complex(1.0, 1.0))
+@test Normed{UInt32,16}(complex(1.0, 0.0))        == 1
+@test Normed{UInt32,16}(Base.TwicePrecision(1.0)) == 1
+

test/runtests.jl

@@ -1,4 +1,4 @@
-using FixedPointNumbers, Compat, Test
+using FixedPointNumbers, Compat.Test
 
 @test isempty(detect_ambiguities(FixedPointNumbers, Base, Core))