From 3c9a45987a31135ff9ff32678776d211586c5bfe Mon Sep 17 00:00:00 2001
From: hrkrshnn <webmail.hari@gmail.com>
Date: Mon, 29 Mar 2021 11:17:49 +0200
Subject: [PATCH] Added c++20 polyfill: erase_if for std::set

---
 libsolutil/cxx20.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/libsolutil/cxx20.h b/libsolutil/cxx20.h
index bbe9817aa..6d96ddeb8 100644
--- a/libsolutil/cxx20.h
+++ b/libsolutil/cxx20.h
@@ -49,4 +49,19 @@ erase_if(std::unordered_map<Key, T, Hash, KeyEqual, Alloc>& _c, Pred _pred)
 	return old_size - _c.size();
 }
 
+// Taken from https://en.cppreference.com/w/cpp/container/set/erase_if
+template<class Key, class Compare, class Alloc, class Pred>
+typename std::set<Key,Compare,Alloc>::size_type
+erase_if(std::set<Key,Compare,Alloc>& c, Pred pred)
+{
+	auto old_size = c.size();
+	for (auto i = c.begin(), last = c.end(); i != last; )
+		if (pred(*i))
+			i = c.erase(i);
+		else
+			++i;
+
+	return old_size - c.size();
+}
+
 }