From c3b032626c841e180e67aed6093397b8caafbd6c Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Thu, 13 Oct 2022 20:00:30 +0100
Subject: Support searching node network by vec3 position

---
 lib/sorting.hpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

(limited to 'lib')

diff --git a/lib/sorting.hpp b/lib/sorting.hpp
index 6b9be6a..0604aaf 100644
--- a/lib/sorting.hpp
+++ b/lib/sorting.hpp
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <type_traits>
+
 template<typename T> struct PtrSorter {
 	bool
 	operator()(const T & a, const T & b) const
@@ -7,3 +9,22 @@ template<typename T> struct PtrSorter {
 		return *a < *b;
 	}
 };
+
+template<typename T, auto M> struct PtrMemberSorter : public PtrSorter<T> {
+	using MT = std::decay_t<decltype((*T {}).*M)>;
+	using is_transparent = MT;
+
+	using PtrSorter<T>::operator();
+
+	bool
+	operator()(const MT & a, const T & b) const
+	{
+		return a < (*b).*M;
+	}
+
+	bool
+	operator()(const T & a, const MT & b) const
+	{
+		return (*a).*M < b;
+	}
+};
-- 
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