Dict generation: use fieldtype instead of .parameters

Author: rfourquet

src/containers.jl

@@ -20,8 +20,8 @@ end
 
 rand!(rng::AbstractRNG, A::AbstractDict{K,V}, sp::Sampler) where {K,V} = _rand!(rng, A, length(A), sp)
 
-rand(rng::AbstractRNG, dist::Distribution{<:Pair}, ::Type{T}, n::Integer) where {T<:AbstractDict} =
-    _rand!(rng, deduce_type(T, eltype(dist).parameters...)(), n, Sampler(rng, dist))
+rand(rng::AbstractRNG, dist::Distribution{P}, ::Type{T}, n::Integer) where {P<:Pair,T<:AbstractDict} =
+    _rand!(rng, deduce_type(T, fieldtype(P, 1), fieldtype(P, 2))(), n, Sampler(rng, dist))
 
 rand(u::Distribution{<:Pair}, ::Type{T}, n::Integer) where {T<:AbstractDict} = rand(GLOBAL_RNG, u, T, n)
 

test/runtests.jl

@@ -102,3 +102,14 @@ end
         @test collect(Iterators.take(d, 10)) isa Vector{Int}
     end
 end
+
+struct PairDistrib <: RandomExtensions.Distribution{Pair}
+end
+
+Random.rand(rng::AbstractRNG, ::Random.SamplerTrivial{PairDistrib}) = 1=>2
+
+@testset "allow abstract Pair when generating a Dict" begin
+    d = rand(PairDistrib(), Dict, 1)
+    @test d == Dict(1=>2)
+    @test typeof(d) == Dict{Any,Any}
+end