Add clamp(x, T) (#34426)

This is #22235, but with the reversed argument order. ``` julia> clamp( 260, UInt8 ) 0xff ``` Co-authored-by: "arghhhh <[email protected]>"
JuliaLang · Apr 11, 2020 · 1b0e987 · 1b0e987
1 parent 2c18e99
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diff --git a/base/math.jl b/base/math.jl
@@ -68,6 +68,22 @@ 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(x, T)::T
+
+Clamp `x` between `typemin(T)` and `typemax(T)` and convert the result to type `T`.
+
+# Examples
+```jldoctest
+julia> clamp(200, Int8)
+127
+julia> clamp(-200, Int8)
+-128
+```
+"""
+clamp(x, ::Type{T}) where {T<:Integer} = clamp(x, typemin(T), typemax(T)) % T
+
+
 """
     clamp!(array::AbstractArray, lo, hi)
 

diff --git a/test/math.jl b/test/math.jl
@@ -22,6 +22,11 @@ end
 
     @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(-200, Int8) === typemin(Int8)
+    @test clamp(100, Int8) === Int8(100)
+    @test clamp(200, Int8) === typemax(Int8)
+
     begin
         x = [0.0, 1.0, 2.0, 3.0, 4.0]
         clamp!(x, 1, 3)