Add C++ Allocator for libctru linear memory

include/rd7.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <renderd7/Allocator.hpp>
 #include <renderd7/DrawV2.hpp>
 #include <renderd7/Error.hpp>
 #include <renderd7/FileSystem.hpp>

include/renderd7/Allocator.hpp

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <memory>
+#include <3ds.h>
+
+#include <renderd7/Error.hpp>
+
+// Write own LinearAllocator for learning
+
+namespace RenderD7 {
+    template<typename T>
+    class LinearAllocator : public std::allocator<T> {
+        public:
+        typedef size_t size_type;
+        typedef T* pointer;
+        typedef const T* const_pointer;
+
+        template<typename T1>
+        struct rebind {typedef LinearAllocator<T1> other;};
+
+        pointer allocate(size_type n, const void* hint=nullptr) {
+            if(n > this->max_size()) {
+                RenderD7::Error("Linear Allocator: \nBad Alloc -> size is larger than free space!");
+                return nullptr;
+            }
+            return (pointer)linearAlloc(n*sizeof(T));
+        }
+
+        void deallocate(pointer p, size_type) {
+            linearFree((void*)p);
+        }
+
+        size_type max_size() {
+            return linearSpaceFree();
+        }
+
+        LinearAllocator() throw() {}
+        LinearAllocator(const LinearAllocator<T>& a) throw(): std::allocator<T>(a) {}
+        ~LinearAllocator() throw() {}
+    };
+}