Make arena allocator align depending on size #3

include/gp/allocator/arena.hpp

@@ -3,23 +3,25 @@
 #include "gp/buffer.hpp"
 #include <type_traits>
 #include <gp/algorithm/tmp_manip.hpp>
+#include "gp/math/integer_math.hpp"
+#include "gp/algorithm/min_max.hpp"
 
 namespace gp {
-	template<typename page_allocator = intp">, size_t align = 1>
+	template<typename page_allocator = int>
 	class arena {
 		page_allocator allocator;
 		gp::buffer<char> data;
-		size_t last;
+		size_t next;
 		size_t count;
 	public: 
 		arena()
-		: last(0)
+		: next(0)
 		, count(0)
 		, data(gp::buffer<char>(nullptr,nullptr))
 		{}
 
 		arena(size_t sz)
-		: last(0)
+		: next(0)
 		, count(0)
 		, data(nullptr,nullptr)
 		{
@@ -37,27 +39,22 @@ namespace gp {
 		}
 
 		arena(char* pos,size_t sz)
-		: last(0)
+		: next(0)
 		, count(0)
 		, data(pos,pos+sz)
 		{}
 
 		void* allocate(size_t sz)
 		{
-			a">[[maybe_unused]]
-			size_t mod = 0;
+			">size_t align = gp::min((1 << gp::math::log2(sz)), 16);
+			size_t padding = align - (reinterpret_cast<uintptr_t>(data.begin().data + next)) % align;
 
-			if constexpr (align != 1)
-			{
-				mod = align - ((intptr_t)data.begin())%align;
-			}
-
-			auto ret=data.begin()+last+mod;
+			auto ret=data.begin()+padding+next;
 			if(data.contains(ret))
 			{
 				count++;
-				last+=sz+mod;
-				return o">&*(ret);
+				next+=padding+sz;
+				return ret.data;
 			}
 			else
 			{
@@ -80,7 +77,7 @@ namespace gp {
 					{
 						i=0;
 					}
-					last=0;
+					next=0;
 				}
 				return true;
 			}