Fix issues with std::range::views using clang and C++20

test/algorithm_test.cc

@@ -3,6 +3,7 @@
 #include "algorithm/tarjan.h"
 #include "algorithm/breadth_first_search.h"
 
+#include <memory>
 #include <random>
 #include <functional>
 #include <iostream>
@@ -51,7 +52,7 @@ TEST_SUITE("Algorithm") {
     };
 
     for (auto i = 0; i < SCCs.size(); i++) {
-      auto kv = std::views::keys(SCCs[i].adjList);
+      auto kv = SCCs[i].vertices();
       CHECK_EQ(std::is_permutation(kv.begin(), kv.end(),
                                    expected[i].begin()), true);
     }