Make length type match index type in sparse vectors

Author: dkarrasch

stdlib/SparseArrays/src/sparsevector.jl

@@ -15,15 +15,15 @@ import LinearAlgebra: promote_to_array_type, promote_to_arrays_
 Vector type for storing sparse vectors.
 """
 struct SparseVector{Tv,Ti<:Integer} <: AbstractSparseVector{Tv,Ti}
-    n::Int              # Length of the sparse vector
+    n::Ti              # Length of the sparse vector
     nzind::Vector{Ti}   # Indices of stored values
     nzval::Vector{Tv}   # Stored values, typically nonzeros
 
     function SparseVector{Tv,Ti}(n::Integer, nzind::Vector{Ti}, nzval::Vector{Tv}) where {Tv,Ti<:Integer}
         n >= 0 || throw(ArgumentError("The number of elements must be non-negative."))
         length(nzind) == length(nzval) ||
             throw(ArgumentError("index and value vectors must be the same length"))
-        new(convert(Int, n), nzind, nzval)
+        new(convert(Ti, n), nzind, nzval)
     end
 end
 

stdlib/SparseArrays/test/sparsevector.jl

@@ -33,6 +33,9 @@ x1_full[SparseArrays.nonzeroinds(spv_x1)] = nonzeros(spv_x1)
     @test SparseArrays.nonzeroinds(x) == [2, 5, 6]
     @test nonzeros(x) == [1.25, -0.75, 3.5]
     @test count(SparseVector(8, [2, 5, 6], [true,false,true])) == 2
+    y = SparseVector(typemax(Int128), Int128[4], [5])
+    @test y isa SparseVector{Int,Int128}
+    @test @inferred size(y) == (@inferred(length(y)),)
 end
 
 @testset "isstored" begin