Fix #129

Author: blegat

Project.toml

@@ -10,7 +10,7 @@ LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 MutableArithmetics = "d8a4904e-b15c-11e9-3269-09a3773c0cb0"
 
 [compat]
-DataStructures = "0.17"
+DataStructures = "0.17.7"
 MutableArithmetics = "0.2"
 julia = "1"
 

src/operators.jl

@@ -105,7 +105,7 @@ function polynomial_merge!(
         end
         while buffer !== nothing && !isempty(buffer) && j <= n2
             @assert i == k
-            t = DataStructures.front(buffer)
+            t = first(buffer)
             comp = compare_monomials(t, j)
             if comp >= 0
                 if comp > 0