better element type for sparse.^0

I misspoke, in general it does not have the same type as A.

base/sparse/sparsematrix.jl

@@ -572,7 +572,9 @@ end # macro
 (.\)(A::Array, B::SparseMatrixCSC) = (.\)(A, full(B))
 (.\)(A::SparseMatrixCSC, B::SparseMatrixCSC) = (.\)(full(A), full(B))
 
-(.^)(A::SparseMatrixCSC, B::Number) = B==0 ? sparse(ones(eltype(A), A.m, A.n)) : SparseMatrixCSC(A.m, A.n, copy(A.colptr), copy(A.rowval), A.nzval .^ B)
+(.^)(A::SparseMatrixCSC, B::Number) =
+    B==0 ? sparse(ones(typeof(one(eltype(A)).^B), A.m, A.n)) :
+           SparseMatrixCSC(A.m, A.n, copy(A.colptr), copy(A.rowval), A.nzval .^ B)
 (.^)(A::Number, B::SparseMatrixCSC) = (.^)(A, full(B))
 (.^)(A::SparseMatrixCSC, B::Array) = (.^)(full(A), B)
 (.^)(A::Array, B::SparseMatrixCSC) = (.^)(A, full(B))