Converting between integer types

base/math.jl

@@ -59,8 +59,24 @@ clamp(x::X, lo::L, hi::H) where {X,L,H} =
                   convert(promote_type(X,L,H), lo),
                   convert(promote_type(X,L,H), x)))
 
+"""
+    clamp(T, x)
+
+Clamp `x` between `typemin(T)` and `typemax(T)` and convert the result to type `T`.
+
+```jldoctest
+julia> clamp(Int8, 200)
+127
+
+julia> clamp(Int8, -200)
+-128
+```
+"""
+clamp(::Type{T}, x) where {T<:Integer} = clamp(x, typemin(T), typemax(T)) % T
+
 """
     clamp!(array::AbstractArray, lo, hi)
+    clamp!(array::AbstractArray, T)
 
 Restrict values in `array` to the specified range, in-place.
 See also [`clamp`](@ref).

test/math.jl

@@ -15,6 +15,11 @@
 
     @test clamp.([0, 1, 2, 3, 4], 1.0, 3.0) == [1.0, 1.0, 2.0, 3.0, 3.0]
     @test clamp.([0 1; 2 3], 1.0, 3.0) == [1.0 1.0; 2.0 3.0]
+
+    @test clamp(Int8,-200) === typemin(Int8)
+    @test clamp(Int8,100) === Int8(100)
+    @test clamp(Int8,200) === typemax(Int8)
+
     begin
         x = [0.0, 1.0, 2.0, 3.0, 4.0]
         clamp!(x, 1, 3)