Fix Rational{T} constructor for abstract T (#41229)

JuliaLang · Jun 15, 2021 · e34c77b · e34c77b
1 parent 2f1a958
commit e34c77b
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Showing 2 changed files with 8 additions and 3 deletions.
diff --git a/base/rational.jl b/base/rational.jl
@@ -18,21 +18,22 @@ unsafe_rational(num::T, den::T) where {T<:Integer} = unsafe_rational(T, num, den
 unsafe_rational(num::Integer, den::Integer) = unsafe_rational(promote(num, den)...)
 
 @noinline __throw_rational_argerror_typemin(T) = throw(ArgumentError("invalid rational: denominator can't be typemin($T)"))
-function checked_den(num::T, den::T) where T<:Integer
+function checked_den(::Type{T}, num::T, den::T) where T<:Integer
  if signbit(den)
  den = -den
- signbit(den) && __throw_rational_argerror_typemin(T)
+ signbit(den) && __throw_rational_argerror_typemin(typeof(den))
  num = -num
  end
  return unsafe_rational(T, num, den)
 end
+checked_den(num::T, den::T) where T<:Integer = checked_den(T, num, den)
 checked_den(num::Integer, den::Integer) = checked_den(promote(num, den)...)
 
 @noinline __throw_rational_argerror_zero(T) = throw(ArgumentError("invalid rational: zero($T)//zero($T)"))
 function Rational{T}(num::Integer, den::Integer) where T<:Integer
  iszero(den) && iszero(num) && __throw_rational_argerror_zero(T)
  num, den = divgcd(num, den)
- return checked_den(T(num), T(den))
+ return checked_den(T, T(num), T(den))
 end
 
 Rational(n::T, d::T) where {T<:Integer} = Rational{T}(n, d)

diff --git a/test/rational.jl b/test/rational.jl
@@ -618,3 +618,7 @@ end
 @testset "checked_den with different integer types" begin
  @test Base.checked_den(Int8(4), Int32(8)) == Base.checked_den(Int32(4), Int32(8))
 end
+
+@testset "Rational{T} with non-concrete T (issue #41222)" begin
+ @test @inferred(Rational{Integer}(2,3)) isa Rational{Integer}
+end