From 590eee0684007894d96ec95d2cee72ad5950c310 Mon Sep 17 00:00:00 2001
From: ecker <mrq@ecker.tech>
Date: Wed, 10 Jun 2026 21:15:45 -0500
Subject: [PATCH] even more SFINAE abuse shoving the hasher into unordered_map
 (and somewhere along the line scene loading is quicker because of things)

---
 engine/inc/uf/utils/math/hash.h            | 35 +++++++++++++++++++++-
 engine/inc/uf/utils/memory/unordered_map.h |  3 +-
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/engine/inc/uf/utils/math/hash.h b/engine/inc/uf/utils/math/hash.h
index 5033b3e4..72147642 100644
--- a/engine/inc/uf/utils/math/hash.h
+++ b/engine/inc/uf/utils/math/hash.h
@@ -2,6 +2,16 @@
 
 #include <uf/utils/memory/vector.h>
 
+namespace uf {
+	namespace traits {
+		template <typename T, typename = void>
+		struct has_hash_method : std::false_type {};
+
+		template <typename T>
+		struct has_hash_method<T, std::void_t<decltype(std::declval<T>().hash())>> : std::true_type {};
+	}
+}
+
 namespace uf {
 	namespace algo {
 		template<size_t> struct FNV1a;
@@ -18,6 +28,11 @@ namespace uf {
 
 		using FNV = FNV1a<sizeof(size_t)>;
 
+		template<typename T, std::enable_if_t<uf::traits::has_hash_method<T>::value, int> = 0>
+		inline size_t fnv1a(const T& v, size_t hash = FNV::basis) {
+			return (hash ^ v.hash()) * FNV::prime;
+		}
+
 		constexpr size_t fnv1a(const char* str, size_t hash = FNV::basis) {
 			return *str ? fnv1a(str + 1, (hash ^ static_cast<size_t>(static_cast<uint8_t>(*str))) * FNV::prime) : hash;
 		}
@@ -30,7 +45,13 @@ namespace uf {
 			return fnv1a(uf::stl::string_view(str), hash);
 		}
 
-		template<typename T, std::enable_if_t<std::is_trivially_copyable_v<T> && !std::is_array_v<T> && !std::is_pointer_v<T>, int> = 0>
+		template<typename T, std::enable_if_t<
+			std::is_trivially_copyable_v<T> &&
+			!std::is_array_v<T> &&
+			!std::is_pointer_v<T> &&
+			!uf::traits::has_hash_method<T>::value,
+			int
+		> = 0>
 		inline size_t fnv1a(const T& v, size_t hash = FNV::basis) {
 			const uint8_t* bytes = reinterpret_cast<const uint8_t*>(&v);
 			for (size_t i = 0; i < sizeof(T); ++i) {
@@ -44,6 +65,11 @@ namespace uf {
 			return fnv1a(uf::stl::string_view(str, N - 1), hash);
 		}
 
+		template<typename T, std::enable_if_t<std::is_pointer_v<T>, int> = 0>
+		inline size_t fnv1a( const T v, size_t hash = FNV::basis ) {
+			return fnv1a(reinterpret_cast<size_t>(v), hash);
+		}
+
 		template<typename T>
 		inline size_t fnv1a(const uf::stl::vector<T>& values, size_t hash = FNV::basis) {
 			if constexpr (std::is_same_v<T, bool>) {
@@ -63,6 +89,13 @@ namespace uf {
 			}
 			return hash;
 		}
+
+		struct hasher {
+			using is_transparent = void;
+			template<typename T> inline size_t operator()( const T& val ) const noexcept {
+				return uf::algo::fnv1a(val);
+			}
+		};
 	}
 
 
diff --git a/engine/inc/uf/utils/memory/unordered_map.h b/engine/inc/uf/utils/memory/unordered_map.h
index b0245492..61727cd5 100644
--- a/engine/inc/uf/utils/memory/unordered_map.h
+++ b/engine/inc/uf/utils/memory/unordered_map.h
@@ -5,13 +5,14 @@
 
 #include <unordered_map>
 #include "vector.h"
+#include <uf/utils/math/hash.h>
 
 namespace uf {
 	namespace stl {
 		template<
 			class Key,
 			class T,
-			class Hash = std::hash<Key>,
+			class Hash = uf::algo::hasher,
 			class KeyEqual = std::equal_to<Key>,
 		#if UF_MEMORYPOOL_USE_STL_ALLOCATOR
 			class Allocator = std::allocator<std::pair<const Key, T>>