Add support for specifying RoundingMode for round

Author: kimikage

src/FixedPointNumbers.jl

@@ -139,6 +139,15 @@ for f in (:+, :-, :rem, :mod, :mod1, :min, :max)
         $f(x::X, y::X) where {X <: FixedPoint} = X($f(x.i, y.i), 0)
     end
 end
+for (m, f) in ((:(:Nearest), :round),
+               (:(:ToZero), :trunc),
+               (:(:Up), :ceil),
+               (:(:Down), :floor))
+    @eval begin
+        round(x::FixedPoint, ::RoundingMode{$m}) = $f(x)
+        round(::Type{Ti}, x::FixedPoint, ::RoundingMode{$m}) where {Ti <: Integer} = $f(Ti, x)
+    end
+end
 
 # Printing. These are used to generate type-symbols, so we need them
 # before we include any files.

test/fixed.jl

@@ -144,6 +144,16 @@ end
             @test_throws ArgumentError round(typemax(F) - F(0.5) + eps(F))
         end
     end
+    @testset "rounding mode" begin
+        @test round(-1.5Q1f6, RoundNearest) === -2Q1f6
+        @test round(-1.5Q1f6, RoundToZero) === -1Q1f6
+        @test round(-1.5Q1f6, RoundUp) === -1Q1f6
+        @test round(-1.5Q1f6, RoundDown) === -2Q1f6
+        @test round(Int, -1.5Q1f6, RoundNearest) === -2
+        @test round(Int, -1.5Q1f6, RoundToZero) === -1
+        @test round(Int, -1.5Q1f6, RoundUp) === -1
+        @test round(Int, -1.5Q1f6, RoundDown) === -2
+    end
     @test_throws InexactError trunc(UInt, typemin(Q0f7))
     @test_throws InexactError floor(UInt, -eps(Q0f7))
 end

test/normed.jl

@@ -264,6 +264,16 @@ end
         @test_throws ArgumentError ceil(typemax(N))
         @test_throws ArgumentError ceil(floor(typemax(N)) + eps(N))
     end
+    @testset "rounding mode" begin
+        @test round(1.504N1f7, RoundNearest) === 2N1f7
+        @test round(1.504N1f7, RoundToZero) === 1N1f7
+        @test round(1.504N1f7, RoundUp) === 2N1f7
+        @test round(1.504N1f7, RoundDown) === 1N1f7
+        @test round(Int, 1.504N1f7, RoundNearest) === 2
+        @test round(Int, 1.504N1f7, RoundToZero) === 1
+        @test round(Int, 1.504N1f7, RoundUp) === 2
+        @test round(Int, 1.504N1f7, RoundDown) === 1
+    end
 end
 
 @testset "approx" begin