diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8ea7b1a..14b4945 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.25)
-project(blt-gp VERSION 0.1.33)
+project(blt-gp VERSION 0.1.34)
 
 include(CTest)
 
diff --git a/dhat.out.293761 b/dhat.out.293761
index 51e9381..21dd56d 100644
--- a/dhat.out.293761
+++ b/dhat.out.293761
@@ -1302,7 +1302,7 @@
  ,"0x4845DA0: memalign (in /usr/libexec/valgrind/vgpreload_dhat-amd64-linux.so)"
  ,"0x129674: std::_Function_handler<void (void*, blt::gp::stack_allocator&, blt::gp::stack_allocator&), blt::gp::operation_t<lit::{lambda()#1}, float ()>::make_callable<context>() const::{lambda(void*, blt::gp::stack_allocator&, blt::gp::stack_allocator&)#1}>::_M_invoke(std::_Any_data const&, void*&&, blt::gp::stack_allocator&, blt::gp::stack_allocator&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x158664: blt::gp::tree_t blt::gp::create_tree<blt::gp::grow_generator_t::generate(blt::gp::generator_arguments const&)::{lambda(blt::gp::gp_program&, std::stack<blt::gp::stack, std::deque<blt::gp::stack, std::allocator<blt::gp::stack> > >&, blt::gp::type_id, unsigned long)#1}>(blt::gp::grow_generator_t::generate(blt::gp::generator_arguments const&)::{lambda(blt::gp::gp_program&, std::stack<blt::gp::stack, std::deque<blt::gp::stack, std::allocator<blt::gp::stack> > >&, blt::gp::type_id, unsigned long)#1}&&, blt::gp::generator_arguments const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
- ,"0x15D0C0: void std::vector<blt::gp::individual, std::allocator<blt::gp::individual> >::_M_realloc_insert<blt::gp::tree_t>(__gnu_cxx::__normal_iterator<blt::gp::individual*, std::vector<blt::gp::individual, std::allocator<blt::gp::individual> > >, blt::gp::tree_t&&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
+ ,"0x15D0C0: void std::vector<blt::gp::individual_t, std::allocator<blt::gp::individual_t> >::_M_realloc_insert<blt::gp::tree_t>(__gnu_cxx::__normal_iterator<blt::gp::individual_t*, std::vector<blt::gp::individual_t, std::allocator<blt::gp::individual_t> > >, blt::gp::tree_t&&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x15CCFA: blt::gp::ramped_half_initializer_t::generate(blt::gp::initializer_arguments const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x15A9F0: blt::gp::tree_t blt::gp::create_tree<blt::gp::full_generator_t::generate(blt::gp::generator_arguments const&)::{lambda(blt::gp::gp_program&, std::stack<blt::gp::stack, std::deque<blt::gp::stack, std::allocator<blt::gp::stack> > >&, blt::gp::type_id, unsigned long)#1}>(blt::gp::full_generator_t::generate(blt::gp::generator_arguments const&)::{lambda(blt::gp::gp_program&, std::stack<blt::gp::stack, std::deque<blt::gp::stack, std::allocator<blt::gp::stack> > >&, blt::gp::type_id, unsigned long)#1}&&, blt::gp::generator_arguments const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x15C977: blt::gp::ramped_half_initializer_t::generate(blt::gp::initializer_arguments const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
@@ -1330,7 +1330,7 @@
  ,"0x1548AB: blt::gp::crossover_t::apply(blt::gp::gp_program&, blt::gp::tree_t const&, blt::gp::tree_t const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x1549A7: blt::gp::crossover_t::apply(blt::gp::gp_program&, blt::gp::tree_t const&, blt::gp::tree_t const&) (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127C77: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
- ,"0x1268EF: blt::gp::individual& std::vector<blt::gp::individual, std::allocator<blt::gp::individual> >::emplace_back<blt::gp::individual>(blt::gp::individual&&) [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
+ ,"0x1268EF: blt::gp::individual_t& std::vector<blt::gp::individual_t, std::allocator<blt::gp::individual_t> >::emplace_back<blt::gp::individual_t>(blt::gp::individual_t&&) [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127DDE: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127F26: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127FE6: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
@@ -1366,7 +1366,7 @@
  ,"0x1247AC: main (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x12497D: main (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x124A4A: main (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
- ,"0x126AFC: blt::gp::individual& std::vector<blt::gp::individual, std::allocator<blt::gp::individual> >::emplace_back<blt::gp::tree_t>(blt::gp::tree_t&&) [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
+ ,"0x126AFC: blt::gp::individual_t& std::vector<blt::gp::individual_t, std::allocator<blt::gp::individual_t> >::emplace_back<blt::gp::tree_t>(blt::gp::tree_t&&) [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127AE9: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127E76: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
  ,"0x127EAF: blt::gp::default_next_pop_creator<blt::gp::select_tournament_t, blt::gp::select_tournament_t, blt::gp::select_tournament_t>::{lambda(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&)#1}::operator()(blt::gp::selector_args&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&, blt::gp::select_tournament_t&&) const [clone .isra.0] (in /home/brett/Documents/code/c++/blt-gp/cmake-build-release/blt-SR-playground-example)"
diff --git a/examples/rice_classification.cpp b/examples/rice_classification.cpp
index 2631a79..e373812 100644
--- a/examples/rice_classification.cpp
+++ b/examples/rice_classification.cpp
@@ -199,7 +199,7 @@ struct test_results_t
     }
 };
 
-test_results_t test_individual(blt::gp::individual& i)
+test_results_t test_individual(blt::gp::individual_t& i)
 {
     test_results_t results;
     
@@ -307,7 +307,7 @@ int main(int argc, const char** argv)
     
     BLT_END_INTERVAL("Rice Classification", "Main");
     
-    std::vector<std::pair<test_results_t, blt::gp::individual*>> results;
+    std::vector<std::pair<test_results_t, blt::gp::individual_t*>> results;
     for (auto& i : program.get_current_pop().get_individuals())
         results.emplace_back(test_individual(i), &i);
     std::sort(results.begin(), results.end(), [](const auto& a, const auto& b) {
diff --git a/include/blt/gp/fwdecl.h b/include/blt/gp/fwdecl.h
index 2c41f91..a00407f 100644
--- a/include/blt/gp/fwdecl.h
+++ b/include/blt/gp/fwdecl.h
@@ -22,16 +22,22 @@
 #include <functional>
 #include <blt/std/logging.h>
 #include <blt/std/types.h>
+#include <blt/gp/stats.h>
 #include <ostream>
-#include <optional>
+#include <cstdlib>
 
 namespace blt::gp
 {
+    inline allocation_tracker_t tracker;
     
     class gp_program;
     
     class type;
     
+    struct operator_id;
+    
+    struct type_id;
+    
     class type_provider;
     
     struct op_container_t;
@@ -40,6 +46,8 @@ namespace blt::gp
     
     class tree_t;
     
+    struct individual_t;
+    
     class population_t;
     
     class tree_generator_t;
@@ -50,6 +58,112 @@ namespace blt::gp
     
     class stack_allocator;
     
+    template<typename T>
+    class tracked_allocator_t;
+    
+    template<typename T>
+    using tracked_vector = std::vector<T, tracked_allocator_t<T>>;
+    
+//    using operation_vector_t = tracked_vector<op_container_t>;
+//    using individual_vector_t = tracked_vector<individual_t, tracked_allocator_t<individual_t>>;
+//    using tree_vector_t = tracked_vector<tree_t>;
+    
+    class aligned_allocator
+    {
+        public:
+            void* allocate(blt::size_t bytes) // NOLINT
+            {
+#ifdef BLT_TRACK_ALLOCATIONS
+                tracker.allocate(bytes);
+#endif
+                return std::aligned_alloc(8, bytes);
+            }
+            
+            void deallocate(void* ptr, blt::size_t bytes) // NOLINT
+            {
+                if (ptr == nullptr)
+                    return;
+#ifdef BLT_TRACK_ALLOCATIONS
+                tracker.deallocate(bytes);
+#else
+                (void) bytes;
+#endif
+                std::free(ptr);
+            }
+    };
+    
+    template<typename T>
+    class tracked_allocator_t
+    {
+        public:
+            using value_type = T;
+            using reference = T&;
+            using const_reference = const T&;
+            using pointer = T*;
+            using const_pointer = const T*;
+            using void_pointer = void*;
+            using const_void_pointer = const void*;
+            using difference_type = blt::ptrdiff_t;
+            using size_type = blt::size_t;
+            template<class U>
+            struct rebind
+            {
+                typedef tracked_allocator_t<U> other;
+            };
+            
+            pointer allocate(size_type n)
+            {
+#ifdef BLT_TRACK_ALLOCATIONS
+                tracker.allocate(n * sizeof(T));
+#endif
+                return static_cast<pointer>(std::malloc(n * sizeof(T)));
+            }
+            
+            pointer allocate(size_type n, const_void_pointer)
+            {
+                return allocate(n);
+            }
+            
+            void deallocate(pointer p, size_type n)
+            {
+#ifdef BLT_TRACK_ALLOCATIONS
+                tracker.deallocate(n * sizeof(T));
+#else
+                (void) n;
+#endif
+                std::free(p);
+            }
+            
+            template<class U, class... Args>
+            void construct(U* p, Args&& ... args)
+            {
+                new(p) T(args...);
+            }
+            
+            template<class U>
+            void destroy(U* p)
+            {
+                p->~T();
+            }
+            
+            [[nodiscard]] size_type max_size() const noexcept
+            {
+                return std::numeric_limits<size_type>::max();
+            }
+    };
+    
+    template<class T1, class T2>
+    inline static bool operator==(const tracked_allocator_t<T1>& lhs, const tracked_allocator_t<T2>& rhs) noexcept
+    {
+        return &lhs == &rhs;
+    }
+    
+    template<class T1, class T2>
+    inline static bool operator!=(const tracked_allocator_t<T1>& lhs, const tracked_allocator_t<T2>& rhs) noexcept
+    {
+        return &lhs != &rhs;
+    }
+    
     namespace detail
     {
         class operator_storage_test;
@@ -66,6 +180,9 @@ namespace blt::gp
         };
         
         using destroy_func_t = std::function<void(destroy_t, stack_allocator&)>;
+        
+        using const_op_iter_t = tracked_vector<op_container_t>::const_iterator;
+        using op_iter_t = tracked_vector<op_container_t>::iterator;
     }
     
 }
diff --git a/include/blt/gp/program.h b/include/blt/gp/program.h
index c15cc64..b95c341 100644
--- a/include/blt/gp/program.h
+++ b/include/blt/gp/program.h
@@ -409,7 +409,7 @@ namespace blt::gp
                                 }
                                 if (thread_helper.next_gen_left > 0)
                                 {
-                                    static thread_local std::vector<tree_t> new_children;
+                                    static thread_local tracked_vector<tree_t> new_children;
                                     new_children.clear();
                                     auto args = get_selector_args(new_children);
                                     
@@ -486,7 +486,7 @@ namespace blt::gp
                                 }
                                 if (thread_helper.next_gen_left > 0)
                                 {
-                                    static thread_local std::vector<tree_t> new_children;
+                                    static thread_local tracked_vector<tree_t> new_children;
                                     new_children.clear();
                                     auto args = get_selector_args(new_children);
                                     if (id == 0)
@@ -593,11 +593,11 @@ namespace blt::gp
             template<blt::size_t size>
             auto get_best_individuals()
             {
-                return convert_array<std::array<std::reference_wrapper<individual>, size>>(get_best_indexes<size>(),
-                                                                                           [this](auto&& arr, blt::size_t index) -> individual& {
+                return convert_array<std::array<std::reference_wrapper<individual_t>, size>>(get_best_indexes<size>(),
+                                                                                             [this](auto&& arr, blt::size_t index) -> individual_t& {
                                                                                                return current_pop.get_individuals()[arr[index]];
                                                                                            },
-                                                                                           std::make_integer_sequence<blt::size_t, size>());
+                                                                                             std::make_integer_sequence<blt::size_t, size>());
             }
             
             [[nodiscard]] bool should_terminate() const
@@ -751,7 +751,7 @@ namespace blt::gp
             // for convenience, shouldn't decrease performance too much
             std::atomic<std::function<void(blt::size_t)>*> thread_execution_service = nullptr;
             
-            inline selector_args get_selector_args(std::vector<tree_t>& next_pop_trees)
+            inline selector_args get_selector_args(tracked_vector<tree_t>& next_pop_trees)
             {
                 return {*this, next_pop_trees, current_pop, current_stats, config, get_random()};
             }
diff --git a/include/blt/gp/selection.h b/include/blt/gp/selection.h
index e23cc6e..2b6b64c 100644
--- a/include/blt/gp/selection.h
+++ b/include/blt/gp/selection.h
@@ -32,7 +32,7 @@ namespace blt::gp
     struct selector_args
     {
         gp_program& program;
-        std::vector<tree_t>& next_pop;
+        tracked_vector<tree_t>& next_pop;
         population_t& current_pop;
         population_stats& current_stats;
         prog_config_t& config;
@@ -44,7 +44,8 @@ namespace blt::gp
         
         if (config.elites > 0)
         {
-            std::vector<std::pair<std::size_t, double>> values;
+            static thread_local tracked_vector<std::pair<std::size_t, double>> values;
+            values.clear();
             
             for (blt::size_t i = 0; i < config.elites; i++)
                 values.emplace_back(i, current_pop.get_individuals()[i].fitness.adjusted_fitness);
@@ -178,7 +179,7 @@ namespace blt::gp
             explicit select_tournament_t(blt::size_t selection_size = 3): selection_size(selection_size)
             {
                 if (selection_size == 0)
-                    BLT_ABORT("Unable to select with this size. Must select at least 1 individual!");
+                    BLT_ABORT("Unable to select with this size. Must select at least 1 individual_t!");
             }
             
             tree_t& select(gp_program& program, population_t& pop, population_stats& stats) final;
diff --git a/include/blt/gp/stack.h b/include/blt/gp/stack.h
index 2ecb12c..6ee7e0a 100644
--- a/include/blt/gp/stack.h
+++ b/include/blt/gp/stack.h
@@ -27,6 +27,7 @@
 #include <blt/std/ranges.h>
 #include <blt/std/meta.h>
 #include <blt/gp/fwdecl.h>
+#include <blt/gp/stats.h>
 #include <utility>
 #include <stdexcept>
 #include <cstdlib>
@@ -37,141 +38,11 @@
 
 namespace blt::gp
 {
-    
     namespace detail
     {
         BLT_META_MAKE_FUNCTION_CHECK(drop);
     }
     
-    class allocation_tracker_t
-    {
-        public:
-            struct allocation_data_t
-            {
-                blt::u64 start_allocations = 0;
-                blt::u64 start_deallocations = 0;
-                blt::u64 start_allocated_bytes = 0;
-                blt::u64 start_deallocated_bytes = 0;
-                
-                blt::u64 end_allocations = 0;
-                blt::u64 end_deallocations = 0;
-                blt::u64 end_allocated_bytes = 0;
-                blt::u64 end_deallocated_bytes = 0;
-                
-                [[nodiscard]] blt::u64 getAllocationDifference() const
-                {
-                    return end_allocations - start_allocations;
-                }
-                
-                [[nodiscard]] blt::u64 getDeallocationDifference() const
-                {
-                    return end_deallocations - start_deallocations;
-                }
-                
-                [[nodiscard]] blt::u64 getAllocatedByteDifference() const
-                {
-                    return end_allocated_bytes - start_allocated_bytes;
-                }
-                
-                [[nodiscard]] blt::u64 getDeallocatedByteDifference() const
-                {
-                    return end_deallocated_bytes - start_deallocated_bytes;
-                }
-            };
-            
-            void allocate(blt::size_t bytes)
-            {
-                allocations++;
-                allocated_bytes += bytes;
-            }
-            
-            void deallocate(blt::size_t bytes)
-            {
-                deallocations++;
-                deallocated_bytes += bytes;
-            }
-            
-            [[nodiscard]] blt::u64 getAllocations() const
-            {
-                return allocations;
-            }
-            
-            [[nodiscard]] blt::u64 getDeallocations() const
-            {
-                return deallocations;
-            }
-            
-            [[nodiscard]] blt::u64 getAllocatedBytes() const
-            {
-                return allocated_bytes;
-            }
-            
-            [[nodiscard]] blt::u64 getDeallocatedBytes() const
-            {
-                return deallocated_bytes;
-            }
-            
-            [[nodiscard]] blt::u64 getAllocationDifference() const
-            {
-                return std::abs(static_cast<blt::i64>(getAllocations()) - static_cast<blt::i64>(getDeallocations()));
-            }
-            
-            [[nodiscard]] blt::u64 getCurrentlyAllocatedBytes() const
-            {
-                return getAllocatedBytes() - getDeallocatedBytes();
-            }
-            
-            [[nodiscard]] allocation_data_t start_measurement() const
-            {
-                allocation_data_t data{};
-                data.start_allocations = allocations;
-                data.start_deallocations = deallocations;
-                data.start_allocated_bytes = allocated_bytes;
-                data.start_deallocated_bytes = deallocated_bytes;
-                return data;
-            }
-            
-            void stop_measurement(allocation_data_t& data) const
-            {
-                data.end_allocations = allocations;
-                data.end_deallocations = deallocations;
-                data.end_allocated_bytes = allocated_bytes;
-                data.end_deallocated_bytes = deallocated_bytes;
-            }
-        
-        private:
-            std::atomic_uint64_t allocations = 0;
-            std::atomic_uint64_t deallocations = 0;
-            std::atomic_uint64_t allocated_bytes = 0;
-            std::atomic_uint64_t deallocated_bytes = 0;
-    };
-    
-    inline allocation_tracker_t tracker;
-    
-    class aligned_allocator
-    {
-        public:
-            void* allocate(blt::size_t bytes) // NOLINT
-            {
-#ifdef BLT_TRACK_ALLOCATIONS
-                tracker.allocate(bytes);
-#endif
-                return std::aligned_alloc(8, bytes);
-            }
-            
-            void deallocate(void* ptr, blt::size_t bytes) // NOLINT
-            {
-                if (ptr == nullptr)
-                    return;
-#ifdef BLT_TRACK_ALLOCATIONS
-                tracker.deallocate(bytes);
-#else
-                (void) bytes;
-#endif
-                std::free(ptr);
-            }
-    };
-    
     class stack_allocator
     {
             constexpr static blt::size_t PAGE_SIZE = 0x100;
diff --git a/include/blt/gp/stats.h b/include/blt/gp/stats.h
new file mode 100644
index 0000000..64b3f13
--- /dev/null
+++ b/include/blt/gp/stats.h
@@ -0,0 +1,134 @@
+#pragma once
+/*
+ *  Copyright (C) 2024  Brett Terpstra
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef BLT_GP_STATS_H
+#define BLT_GP_STATS_H
+
+#include <blt/std/types.h>
+#include <atomic>
+#include <cmath>
+
+namespace blt::gp
+{
+    
+    class allocation_tracker_t
+    {
+        public:
+            struct allocation_data_t
+            {
+                blt::u64 start_allocations = 0;
+                blt::u64 start_deallocations = 0;
+                blt::u64 start_allocated_bytes = 0;
+                blt::u64 start_deallocated_bytes = 0;
+                
+                blt::u64 end_allocations = 0;
+                blt::u64 end_deallocations = 0;
+                blt::u64 end_allocated_bytes = 0;
+                blt::u64 end_deallocated_bytes = 0;
+                
+                [[nodiscard]] blt::u64 getAllocationDifference() const
+                {
+                    return end_allocations - start_allocations;
+                }
+                
+                [[nodiscard]] blt::u64 getDeallocationDifference() const
+                {
+                    return end_deallocations - start_deallocations;
+                }
+                
+                [[nodiscard]] blt::u64 getAllocatedByteDifference() const
+                {
+                    return end_allocated_bytes - start_allocated_bytes;
+                }
+                
+                [[nodiscard]] blt::u64 getDeallocatedByteDifference() const
+                {
+                    return end_deallocated_bytes - start_deallocated_bytes;
+                }
+            };
+            
+            void allocate(blt::size_t bytes)
+            {
+                allocations++;
+                allocated_bytes += bytes;
+            }
+            
+            void deallocate(blt::size_t bytes)
+            {
+                deallocations++;
+                deallocated_bytes += bytes;
+            }
+            
+            [[nodiscard]] blt::u64 getAllocations() const
+            {
+                return allocations;
+            }
+            
+            [[nodiscard]] blt::u64 getDeallocations() const
+            {
+                return deallocations;
+            }
+            
+            [[nodiscard]] blt::u64 getAllocatedBytes() const
+            {
+                return allocated_bytes;
+            }
+            
+            [[nodiscard]] blt::u64 getDeallocatedBytes() const
+            {
+                return deallocated_bytes;
+            }
+            
+            [[nodiscard]] blt::u64 getAllocationDifference() const
+            {
+                return std::abs(static_cast<blt::i64>(getAllocations()) - static_cast<blt::i64>(getDeallocations()));
+            }
+            
+            [[nodiscard]] blt::u64 getCurrentlyAllocatedBytes() const
+            {
+                return getAllocatedBytes() - getDeallocatedBytes();
+            }
+            
+            [[nodiscard]] allocation_data_t start_measurement() const
+            {
+                allocation_data_t data{};
+                data.start_allocations = allocations;
+                data.start_deallocations = deallocations;
+                data.start_allocated_bytes = allocated_bytes;
+                data.start_deallocated_bytes = deallocated_bytes;
+                return data;
+            }
+            
+            void stop_measurement(allocation_data_t& data) const
+            {
+                data.end_allocations = allocations;
+                data.end_deallocations = deallocations;
+                data.end_allocated_bytes = allocated_bytes;
+                data.end_deallocated_bytes = deallocated_bytes;
+            }
+        
+        private:
+            std::atomic_uint64_t allocations = 0;
+            std::atomic_uint64_t deallocations = 0;
+            std::atomic_uint64_t allocated_bytes = 0;
+            std::atomic_uint64_t deallocated_bytes = 0;
+    };
+    
+}
+
+#endif //BLT_GP_STATS_H
diff --git a/include/blt/gp/transformers.h b/include/blt/gp/transformers.h
index a2524f1..e004afa 100644
--- a/include/blt/gp/transformers.h
+++ b/include/blt/gp/transformers.h
@@ -29,8 +29,6 @@ namespace blt::gp
 {
     namespace detail
     {
-        using op_iter = std::vector<blt::gp::op_container_t>::iterator;
-        
         template<typename T>
         inline static constexpr double sum(const T& array)
         {
diff --git a/include/blt/gp/tree.h b/include/blt/gp/tree.h
index 2fc985e..2ed4e3f 100644
--- a/include/blt/gp/tree.h
+++ b/include/blt/gp/tree.h
@@ -53,7 +53,6 @@ namespace blt::gp
     
     class tree_t
     {
-            using iter_type = std::vector<op_container_t>::const_iterator;
         public:
             explicit tree_t(gp_program& program);
             
@@ -66,12 +65,12 @@ namespace blt::gp
                 blt::ptrdiff_t end;
             };
             
-            [[nodiscard]] inline std::vector<op_container_t>& get_operations()
+            [[nodiscard]] inline tracked_vector<op_container_t>& get_operations()
             {
                 return operations;
             }
             
-            [[nodiscard]] inline const std::vector<op_container_t>& get_operations() const
+            [[nodiscard]] inline const tracked_vector<op_container_t>& get_operations() const
             {
                 return operations;
             }
@@ -133,7 +132,7 @@ namespace blt::gp
             blt::ptrdiff_t find_parent(blt::gp::gp_program& program, blt::ptrdiff_t start) const;
             
             // valid for [begin, end)
-            static blt::size_t total_value_bytes(iter_type begin, iter_type end)
+            static blt::size_t total_value_bytes(detail::const_op_iter_t begin, detail::const_op_iter_t end)
             {
                 blt::size_t total = 0;
                 for (auto it = begin; it != end; it++)
@@ -161,7 +160,7 @@ namespace blt::gp
             }
         
         private:
-            std::vector<op_container_t> operations;
+            tracked_vector<op_container_t> operations;
             blt::gp::stack_allocator values;
             detail::eval_func_t* func;
     };
@@ -174,26 +173,26 @@ namespace blt::gp
         blt::i64 hits = 0;
     };
     
-    struct individual
+    struct individual_t
     {
         tree_t tree;
         fitness_t fitness;
         
-        individual() = default;
+        individual_t() = delete;
         
-        explicit individual(tree_t&& tree): tree(std::move(tree))
+        explicit individual_t(tree_t&& tree): tree(std::move(tree))
         {}
         
-        explicit individual(const tree_t& tree): tree(tree)
+        explicit individual_t(const tree_t& tree): tree(tree)
         {}
         
-        individual(const individual&) = default;
+        individual_t(const individual_t&) = default;
         
-        individual(individual&&) = default;
+        individual_t(individual_t&&) = default;
         
-        individual& operator=(const individual&) = delete;
+        individual_t& operator=(const individual_t&) = delete;
         
-        individual& operator=(individual&&) = default;
+        individual_t& operator=(individual_t&&) = default;
     };
     
     struct population_stats
@@ -220,7 +219,7 @@ namespace blt::gp
             class population_tree_iterator
             {
                 public:
-                    population_tree_iterator(std::vector<individual>& ind, blt::size_t pos): ind(ind), pos(pos)
+                    population_tree_iterator(tracked_vector<individual_t>& ind, blt::size_t pos): ind(ind), pos(pos)
                     {}
                     
                     auto begin()
@@ -265,11 +264,11 @@ namespace blt::gp
                     }
                 
                 private:
-                    std::vector<individual>& ind;
+                    tracked_vector<individual_t>& ind;
                     blt::size_t pos;
             };
             
-            std::vector<individual>& get_individuals()
+            tracked_vector<individual_t>& get_individuals()
             {
                 return individuals;
             }
@@ -315,7 +314,7 @@ namespace blt::gp
             population_t& operator=(population_t&&) = default;
         
         private:
-            std::vector<individual> individuals;
+            tracked_vector<individual_t> individuals;
     };
 }
 
diff --git a/src/selection.cpp b/src/selection.cpp
index e94a7f2..5621dc6 100644
--- a/src/selection.cpp
+++ b/src/selection.cpp
@@ -86,7 +86,7 @@ namespace blt::gp
                     return ref.tree;
             }
         }
-        BLT_WARN("Unable to find individual with fitness proportionate. This should not be a possible code path! (%lf)", choice);
+        BLT_WARN("Unable to find individual_t with fitness proportionate. This should not be a possible code path! (%lf)", choice);
         return pop.get_individuals()[0].tree;
         //BLT_ABORT("Unable to find individual");
     }
diff --git a/src/stats.cpp b/src/stats.cpp
new file mode 100644
index 0000000..d5be6a7
--- /dev/null
+++ b/src/stats.cpp
@@ -0,0 +1,24 @@
+/*
+ *  <Short Description>
+ *  Copyright (C) 2024  Brett Terpstra
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+#include <blt/gp/stats.h>
+#include <blt/std/logging.h>
+
+namespace blt::gp
+{
+
+}
\ No newline at end of file
diff --git a/src/transformers.cpp b/src/transformers.cpp
index 149a5d4..4994fb3 100644
--- a/src/transformers.cpp
+++ b/src/transformers.cpp
@@ -36,7 +36,7 @@ namespace blt::gp
         return new_tree;
     }
     
-    inline blt::size_t accumulate_type_sizes(detail::op_iter begin, detail::op_iter end)
+    inline blt::size_t accumulate_type_sizes(detail::op_iter_t begin, detail::op_iter_t end)
     {
         blt::size_t total = 0;
         for (auto it = begin; it != end; ++it)