Add helper for sorting sorted containers by a projection

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/sorting.h b/lib/sorting.h
index 777de00..be5a7e2 100644
--- a/lib/sorting.h
+++ b/lib/sorting.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <functional>
 #include <glm/fwd.hpp>
 #include <type_traits>
 
@@ -30,6 +31,14 @@ template<typename T, auto M> struct PtrMemberSorter : public PtrSorter<T> {
 	}
 };
 
+template<auto Proj> struct SortedBy {
+	auto
+	operator()(const auto & left, const auto & right) const
+	{
+		return (std::invoke(Proj, left) < std::invoke(Proj, right));
+	}
+};
+
 struct CompareBy {
 	glm::length_t index;