Make the canReachRoots() traversal non-recursive

1 files changed, 11 insertions, 0 deletions

diff --git a/src/libutil/util.hh b/src/libutil/util.hh
index 76f80f7a4..485ff4153 100644
--- a/src/libutil/util.hh
+++ b/src/libutil/util.hh
@@ -523,6 +523,17 @@ std::optional<typename T::value_type> remove_begin(T & c)
 }
 
 
+/* Remove and return the first item from a container. */
+template <class T>
+std::optional<typename T::value_type> pop(T & c)
+{
+    if (c.empty()) return {};
+    auto v = std::move(c.front());
+    c.pop();
+    return v;
+}
+
+
 template<typename T>
 class Callback;