diff --git a/CMakeLists.txt b/CMakeLists.txt
index 17b1998..f3941d3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.25)
-project(blt-gp VERSION 0.0.25)
+project(blt-gp VERSION 0.0.26)
 
 option(ENABLE_ADDRSAN "Enable the address sanitizer" OFF)
 option(ENABLE_UBSAN "Enable the ub sanitizer" OFF)
@@ -38,7 +38,7 @@ endif ()
 if (${BUILD_EXAMPLES})
     project(blt-gp-example)
 
-    add_executable(blt-gp-example examples/main.cpp)
+    add_executable(blt-gp-example examples/main.cpp examples/gp_test_2.cpp)
 
     target_link_libraries(blt-gp-example PUBLIC BLT blt-gp)
 
diff --git a/examples/gp_test_2.cpp b/examples/gp_test_2.cpp
new file mode 100644
index 0000000..55c1eb3
--- /dev/null
+++ b/examples/gp_test_2.cpp
@@ -0,0 +1,45 @@
+/*
+ *  <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/program.h>
+
+static constexpr long SEED = 41912;
+
+blt::gp::type_system type_system;
+std::random_device dev;
+blt::gp::gp_program program(type_system, std::mt19937_64{SEED}); // NOLINT
+
+blt::gp::operation_t add([](float a, float b) { return a + b; });
+blt::gp::operation_t sub([](float a, float b) { return a - b; });
+blt::gp::operation_t mul([](float a, float b) { return a * b; });
+blt::gp::operation_t pro_div([](float a, float b) { return b == 0 ? 0.0f : a / b; });
+blt::gp::operation_t lit([]() {
+    static std::uniform_real_distribution<float> dist(-32000, 32000);
+    return dist(program.get_random());
+});
+
+int main()
+{
+    type_system.register_type<float>();
+    type_system.register_type<bool>();
+    
+    type_system.add_operator(add);
+    type_system.add_operator(sub);
+    type_system.add_operator(mul);
+    type_system.add_operator(pro_div);
+    type_system.add_operator(lit);
+}
\ No newline at end of file
diff --git a/examples/main.cpp b/examples/main.cpp
index c01a72b..10b3db5 100644
--- a/examples/main.cpp
+++ b/examples/main.cpp
@@ -272,121 +272,130 @@ void test()
     
 }
 
-blt::gp::type_system type_system;
-blt::gp::gp_program program(type_system);
-std::random_device dev;
-std::mt19937_64 engine{dev()};
-
-blt::gp::operation_t add([](float a, float b) { return a + b; });
-blt::gp::operation_t sub([](float a, float b) { return a - b; });
-blt::gp::operation_t mul([](float a, float b) { return a * b; });
-blt::gp::operation_t pro_div([](float a, float b) { return b == 0 ? 0.0f : a / b; });
-blt::gp::operation_t lit([]() {
-    static std::uniform_real_distribution<float> dist(-32000, 32000);
-    return dist(engine);
-});
-
-
-int main()
+float nyah(float a, int b, bool c)
 {
-    type_system.register_type<float>();
-    type_system.register_type<bool>();
+    return a + static_cast<float>(b) * c;
+}
+
+struct silly
+{
+    unsigned long bruh;
+    int nya;
     
-    program.add_operator(add);
-    program.add_operator(sub);
-    program.add_operator(mul);
-    program.add_operator(pro_div);
-    program.add_operator(lit);
+    friend std::ostream& operator<<(std::ostream& out, const silly& s)
+    {
+        out << "[" << s.bruh << " " << s.nya << "]";
+        return out;
+    }
+};
 
-//    constexpr blt::size_t MAX_ALIGNMENT = 8;
-//    test();
-//    std::cout << alignof(silly) << " " << sizeof(silly) << std::endl;
-//    std::cout << alignof(super_large) << " " << sizeof(super_large) << " " << ((sizeof(super_large) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1))
-//              << std::endl;
-//    std::cout << ((sizeof(char) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << " "
-//              << ((sizeof(short) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << std::endl;
-//    std::cout << ((sizeof(int) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << " " << ((sizeof(long) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1))
-//              << std::endl;
-//    std::cout << alignof(void*) << " " << sizeof(void*) << std::endl;
-//    std::cout << blt::type_string<decltype(&"SillString")>() << std::endl;
-//
-//    alloc.push(50);
-//    alloc.push(550.3f);
-//    alloc.push(20.1230345);
-//    alloc.push(true);
-//    alloc.push(false);
-//    alloc.push(std::string("SillyString"));
-//    alloc.push(&"SillyString");
-//
-//    std::cout << std::endl;
-//    std::cout << *alloc.pop<decltype(&"SillString")>() << std::endl;
-//    std::cout << alloc.pop<std::string>() << std::endl;
-//    std::cout << alloc.pop<bool>() << std::endl;
-//    std::cout << alloc.pop<bool>() << std::endl;
-//    std::cout << alloc.pop<double>() << std::endl;
-//    std::cout << alloc.pop<float>() << std::endl;
-//    std::cout << alloc.pop<int>() << std::endl;
-//    std::cout << std::endl;
-//
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    alloc.push(silly{});
-//    alloc.push(large{});
-//    alloc.push(super_large{});
-//    alloc.push(silly{25, 24});
-//    alloc.push(large{});
-//
-//    std::cout << std::endl;
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    alloc.pop<large>();
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    std::cout << alloc.pop<silly>() << std::endl;
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    alloc.pop<super_large>();
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    alloc.pop<large>();
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
-//    std::cout << alloc.pop<silly>() << std::endl;
-//    std::cout << std::endl;
-//
-//    std::cout << "Is empty? " << alloc.empty() << " bytes left: " << alloc.bytes_in_head() << std::endl;
-//    std::cout << std::endl;
-//
-//    alloc.push(silly{2, 5});
-//    alloc.push(large{});
-//    alloc.push(super_large{});
-//    alloc.push(silly{80, 10});
-//    alloc.push(large{});
-//    alloc.push(50);
-//    alloc.push(550.3f);
-//    alloc.push(20.1230345);
-//    alloc.push(std::string("SillyString"));
-//    alloc.push(33.22f);
-//    alloc.push(120);
-//    alloc.push(true);
-//
-//    blt::gp::operation_t<float(float, int, bool)> silly_op(nyah);
-//    blt::gp::operation_t<float(float, float)> silly_op_2([](float f, float g) {
-//        return f + g;
-//    });
+struct large
+{
+    unsigned char data[256];
+};
 
-//    std::cout << silly_op(alloc) << std::endl;
-//
-//    std::cout << "Is empty? " << alloc.empty() << std::endl;
+struct super_large
+{
+    unsigned char data[5129];
+};
 
-//    std::cout << std::endl;
-//
-//    //auto* pointer = static_cast<void*>(head->metadata.offset);
-//    //return std::align(alignment, bytes, pointer, remaining_bytes);
-//
-//    float f = 10.5;
-//    int i = 412;
-//    bool b = true;
-//
-//    std::array<void*, 3> arr{reinterpret_cast<void*>(&f), reinterpret_cast<void*>(&i), reinterpret_cast<void*>(&b)};
-//
-//    blt::span<void*, 3> spv{arr};
-//
-//    std::cout << silly_op.operator()(spv) << std::endl;
+blt::gp::stack_allocator alloc;
+
+int main_old()
+{
+    constexpr blt::size_t MAX_ALIGNMENT = 8;
+    test();
+    std::cout << alignof(silly) << " " << sizeof(silly) << std::endl;
+    std::cout << alignof(super_large) << " " << sizeof(super_large) << " " << ((sizeof(super_large) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1))
+              << std::endl;
+    std::cout << ((sizeof(char) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << " "
+              << ((sizeof(short) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << std::endl;
+    std::cout << ((sizeof(int) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1)) << " " << ((sizeof(long) + (MAX_ALIGNMENT - 1)) & ~(MAX_ALIGNMENT - 1))
+              << std::endl;
+    std::cout << alignof(void*) << " " << sizeof(void*) << std::endl;
+    std::cout << blt::type_string<decltype(&"SillString")>() << std::endl;
     
-    //std::cout << "Hello World!" << std::endl;
+    alloc.push(50);
+    alloc.push(550.3f);
+    alloc.push(20.1230345);
+    alloc.push(true);
+    alloc.push(false);
+    alloc.push(std::string("SillyString"));
+    alloc.push(&"SillyString");
+    
+    std::cout << std::endl;
+    std::cout << *alloc.pop<decltype(&"SillString")>() << std::endl;
+    std::cout << alloc.pop<std::string>() << std::endl;
+    std::cout << alloc.pop<bool>() << std::endl;
+    std::cout << alloc.pop<bool>() << std::endl;
+    std::cout << alloc.pop<double>() << std::endl;
+    std::cout << alloc.pop<float>() << std::endl;
+    std::cout << alloc.pop<int>() << std::endl;
+    std::cout << std::endl;
+    
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    alloc.push(silly{});
+    alloc.push(large{});
+    alloc.push(super_large{});
+    alloc.push(silly{25, 24});
+    alloc.push(large{});
+    
+    std::cout << std::endl;
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    alloc.pop<large>();
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    std::cout << alloc.pop<silly>() << std::endl;
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    alloc.pop<super_large>();
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    alloc.pop<large>();
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    std::cout << alloc.pop<silly>() << std::endl;
+    std::cout << std::endl;
+    
+    std::cout << "Is empty? " << alloc.empty() << " bytes left: " << alloc.bytes_in_head() << std::endl;
+    std::cout << std::endl;
+    
+    alloc.push(silly{2, 5});
+    alloc.push(large{});
+    alloc.push(super_large{});
+    alloc.push(silly{80, 10});
+    alloc.push(large{});
+    alloc.push(50);
+    alloc.push(550.3f);
+    alloc.push(20.1230345);
+    alloc.push(std::string("SillyString"));
+    alloc.push(33.22f);
+    alloc.push(120);
+    alloc.push(true);
+    
+    blt::gp::operation_t silly_op(nyah);
+    blt::gp::operation_t silly_op_2([](float f, float g) {
+        return f + g;
+    });
+    
+    std::cout << silly_op(alloc) << std::endl;
+    
+    std::cout << "Is empty? " << alloc.empty() << std::endl;
+    
+    std::cout << std::endl;
+    
+    //auto* pointer = static_cast<void*>(head->metadata.offset);
+    //return std::align(alignment, bytes, pointer, remaining_bytes);
+    
+    float f = 10.5;
+    int i = 412;
+    bool b = true;
+    
+    alloc.push(f);
+    alloc.push(i);
+    alloc.push(b);
+    
+    //std::array<void*, 3> arr{reinterpret_cast<void*>(&f), reinterpret_cast<void*>(&i), reinterpret_cast<void*>(&b)};
+    
+    //blt::span<void*, 3> spv{arr};
+    
+    std::cout << silly_op.operator()(alloc) << std::endl;
+    
+    std::cout << "Hello World!" << std::endl;
 }
\ No newline at end of file
diff --git a/include/blt/gp/program.h b/include/blt/gp/program.h
index 285d47e..b56e4d6 100644
--- a/include/blt/gp/program.h
+++ b/include/blt/gp/program.h
@@ -45,21 +45,9 @@ namespace blt::gp
     class gp_program
     {
         public:
-            explicit gp_program(type_system system): system(std::move(system))
+            explicit gp_program(type_system& system, std::mt19937_64 engine): system(system), engine(engine)
             {}
             
-            template<typename Return, typename... Args>
-            void add_operator(const operation_t<Return(Args...)>& op)
-            {
-                auto return_type_id = system.get_type<Return>().id();
-                auto& operator_list = op.get_argc() == 0 ? terminals : non_terminals;
-                operator_list[return_type_id].push_back(operators.size());
-                
-                auto operator_index = operators.size();
-                (argument_types[operator_index].push_back(system.get_type<Args>()), ...);
-                operators.push_back(op.make_callable());
-            }
-            
             [[nodiscard]] inline type_system& get_typesystem()
             {
                 return system;
@@ -67,32 +55,15 @@ namespace blt::gp
             
             void generate_tree();
             
-            inline operator_id select_terminal(type_id id, std::mt19937_64& engine)
+            inline std::mt19937_64& get_random()
             {
-                std::uniform_int_distribution<blt::size_t> dist(0, terminals[id].size() - 1);
-                return terminals[id][dist(engine)];
-            }
-            
-            inline operator_id select_non_terminal(type_id id, std::mt19937_64& engine)
-            {
-                std::uniform_int_distribution<blt::size_t> dist(0, non_terminals[id].size() - 1);
-                return non_terminals[id][dist(engine)];
-            }
-            
-            inline std::vector<type>& get_argument_types(operator_id id)
-            {
-                return argument_types[id];
+                return engine;
             }
         
         private:
-            type_system system;
+            type_system& system;
             blt::gp::stack_allocator alloc;
-            // indexed from return TYPE ID, returns index of operator
-            blt::expanding_buffer<std::vector<operator_id>> terminals;
-            blt::expanding_buffer<std::vector<operator_id>> non_terminals;
-            // indexed from OPERATOR ID (operator number)
-            blt::expanding_buffer<std::vector<type>> argument_types;
-            std::vector<std::function<void(stack_allocator&)>> operators;
+            std::mt19937_64 engine;
     };
     
 }
diff --git a/include/blt/gp/stack.h b/include/blt/gp/stack.h
index 1b216f9..ce05dff 100644
--- a/include/blt/gp/stack.h
+++ b/include/blt/gp/stack.h
@@ -24,6 +24,7 @@
 #include <stdexcept>
 #include <cstdlib>
 #include <memory>
+#include <type_traits>
 
 namespace blt::gp
 {
@@ -40,9 +41,10 @@ namespace blt::gp
             template<typename T>
             void push(T&& value)
             {
+                using NO_REF_T = std::remove_reference_t<T>;
                 auto ptr = allocate_bytes<T>();
                 head->metadata.offset = static_cast<blt::u8*>(ptr) + aligned_size<T>();
-                new(ptr) T(std::forward<T>(value));
+                new(ptr) NO_REF_T(std::forward<T>(value));
             }
             
             template<typename T>
diff --git a/include/blt/gp/typesystem.h b/include/blt/gp/typesystem.h
index 6c3f0d4..1be619f 100644
--- a/include/blt/gp/typesystem.h
+++ b/include/blt/gp/typesystem.h
@@ -21,7 +21,13 @@
 
 #include <blt/std/hashmap.h>
 #include <blt/std/types.h>
+#include <blt/std/ranges.h>
+#include <blt/std/utility.h>
+#include <blt/std/memory.h>
 #include <blt/gp/fwdecl.h>
+#include <blt/gp/stack.h>
+#include <blt/gp/operations.h>
+#include <random>
 
 namespace blt::gp
 {
@@ -70,6 +76,10 @@ namespace blt::gp
             std::string name_{};
     };
     
+    /**
+     * Is a provider for the set of types possible in a GP program
+     * also provides a set of functions for converting between C++ types and BLT GP types
+     */
     class type_system
     {
         public:
@@ -87,9 +97,69 @@ namespace blt::gp
             {
                 return types[blt::type_string_raw<T>()];
             }
+            
+            /**
+             * This function is slow btw
+             * @param engine
+             * @return
+             */
+            inline type select_type(std::mt19937_64& engine)
+            {
+                std::uniform_int_distribution dist(0ul, types.size() - 1);
+                auto offset = dist(engine);
+                auto itr = types.begin();
+                for ([[maybe_unused]] auto _ : blt::range(0ul, offset))
+                    itr = itr++;
+                return itr->second;
+            }
+            
+            inline operator_id select_terminal(std::mt19937_64& engine, type_id id)
+            {
+                std::uniform_int_distribution<blt::size_t> dist(0, terminals[id].size() - 1);
+                return terminals[id][dist(engine)];
+            }
+            
+            inline operator_id select_non_terminal(std::mt19937_64& engine, type_id id)
+            {
+                std::uniform_int_distribution<blt::size_t> dist(0, non_terminals[id].size() - 1);
+                return non_terminals[id][dist(engine)];
+            }
+            
+            inline std::vector<type>& get_argument_types(operator_id id)
+            {
+                return argument_types[id];
+            }
+            
+            inline std::vector<operator_id>& get_type_terminals(type_id id)
+            {
+                return terminals[id];
+            }
+            
+            inline std::vector<operator_id>& get_type_non_terminals(type_id id)
+            {
+                return non_terminals[id];
+            }
+            
+            template<typename Return, typename... Args>
+            void add_operator(const operation_t<Return(Args...)>& op)
+            {
+                auto return_type_id = get_type<Return>().id();
+                auto& operator_list = op.get_argc() == 0 ? terminals : non_terminals;
+                operator_list[return_type_id].push_back(operators.size());
+                
+                auto operator_index = operators.size();
+                (argument_types[operator_index].push_back(get_type<Args>()), ...);
+                operators.push_back(op.make_callable());
+            }
         
         private:
             blt::hashmap_t<std::string, type> types;
+            // indexed from return TYPE ID, returns index of operator
+            blt::expanding_buffer<std::vector<operator_id>> terminals;
+            blt::expanding_buffer<std::vector<operator_id>> non_terminals;
+            // indexed from OPERATOR ID (operator number)
+            blt::expanding_buffer<std::vector<type>> argument_types;
+            std::vector<std::function<void(stack_allocator&)>> operators;
     };
 }
 
diff --git a/src/generators.cpp b/src/generators.cpp
index 406e039..9bbc46d 100644
--- a/src/generators.cpp
+++ b/src/generators.cpp
@@ -16,19 +16,60 @@
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 #include <blt/gp/generators.h>
+#include <blt/gp/program.h>
+#include <stack>
 
 namespace blt::gp
 {
     
+    struct stack
+    {
+        blt::gp::operator_id id;
+        blt::size_t depth;
+    };
+    
+    static inline std::stack<stack> get_base_generator(gp_program& program)
+    {
+        std::stack<stack> tree_generator;
+        
+        auto& system = program.get_typesystem();
+        // select a type which has a non-empty set of non-terminals
+        type base_type;
+        do
+        {
+            base_type = system.select_type(program.get_random());
+        } while (system.get_type_non_terminals(base_type.id()).empty());
+        
+        tree_generator.emplace(system.select_non_terminal(program.get_random(), base_type.id()), 0);
+        
+        return tree_generator;
+    }
+    
+    template<typename Func>
+    tree_t create_tree(Func func, gp_program& program, blt::size_t min_depth, blt::size_t max_depth)
+    {
+        std::stack<stack> tree_generator = get_base_generator(program);
+        tree_t tree;
+        
+        while (!tree_generator.empty())
+        {
+        
+        }
+        
+        return tree;
+    }
+    
     tree_t grow_generator_t::generate(gp_program& program, blt::size_t min_depth, blt::size_t max_depth)
     {
-        tree_t tree;
-        return tree;
+        return create_tree([]() {
+        
+        }, program, min_depth, max_depth);
     }
     
     tree_t full_generator_t::generate(gp_program& program, blt::size_t min_depth, blt::size_t max_depth)
     {
-        tree_t tree;
-        return tree;
+        return create_tree([]() {
+        
+        }, program, min_depth, max_depth);
     }
 }
\ No newline at end of file