fix JuliaLang#19182: convert([Un]Signed, x::BigInt) (JuliaLang#23474)

tpapp · Sep 8, 2017 · 22987e3 · 22987e3
1 parent bc12af5
commit 22987e3
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/base/gmp.jl b/base/gmp.jl
@@ -229,6 +229,7 @@ widen(::Type{BigInt}) = BigInt
 signed(x::BigInt) = x
 
 convert(::Type{BigInt}, x::BigInt) = x
+convert(::Type{Signed}, x::BigInt) = x
 
 hastypemax(::Type{BigInt}) = false
 
@@ -323,7 +324,7 @@ end
 
 rem(x::Integer, ::Type{BigInt}) = convert(BigInt, x)
 
-function convert(::Type{T}, x::BigInt) where T<:Unsigned
+function convert(::Type{T}, x::BigInt) where T<:Base.BitUnsigned
  if sizeof(T) < sizeof(Limb)
  convert(T, convert(Limb,x))
  else
@@ -332,7 +333,7 @@ function convert(::Type{T}, x::BigInt) where T<:Unsigned
  end
 end
 
-function convert(::Type{T}, x::BigInt) where T<:Signed
+function convert(::Type{T}, x::BigInt) where T<:Base.BitSigned
  n = abs(x.size)
  if sizeof(T) < sizeof(Limb)
  SLimb = typeof(Signed(one(Limb)))

diff --git a/test/bigint.jl b/test/bigint.jl
@@ -374,3 +374,10 @@ end
 
 @test BigInt <: Signed
 @test big(1) isa Signed
+
+let x = big(1)
+ @test signed(x) === x
+ @test convert(Signed, x) === x
+ @test Signed(x) === x
+ @test_throws MethodError convert(Unsigned, x) # could change in the future
+end