diff --git a/build_g.sh b/build_g.sh
index 340e471c..bffbb51f 100644
--- a/build_g.sh
+++ b/build_g.sh
@@ -2,9 +2,17 @@ python prebuild.py
 
 SRC_C=$(find src/ -name "*.c")
 SRC_CPP=$(find src/ -name "*.cpp")
-SRC="$SRC_C $SRC_CPP"
 
-FLAGS="-std=c++17 -O0 -stdlib=libc++ -Iinclude -frtti -Wfatal-errors -g -DDEBUG -DPK_ENABLE_OS=1"
+COMMON_FLAGS="-Iinclude -O0 -Wfatal-errors -g -DDEBUG -DPK_ENABLE_OS=1"
 
-clang++ $FLAGS -o main src2/main.cpp $SRC
+FLAGS_C="-std=c11 $COMMON_FLAGS"
+FLAGS_CPP="-std=c++17 -stdlib=libc++ -frtti $COMMON_FLAGS"
 
+echo "Compiling C files..."
+clang $FLAGS_C -c $SRC_C
+ar rcs libpocketpy_c.a *.o
+rm *.o
+
+echo "Compiling C++ files..."
+clang++ $FLAGS_CPP -o main src2/main.cpp $SRC_CPP libpocketpy_c.a 
+rm libpocketpy_c.a
diff --git a/include/pocketpy/common/any.h b/include/pocketpy/common/any.h
new file mode 100644
index 00000000..3e7e904b
--- /dev/null
+++ b/include/pocketpy/common/any.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct c11_userdata{
+    void* _0;
+    void* _1;
+} c11_userdata;
+
+void c11_userdata__ctor(c11_userdata* self, void* ptr, int size);
+#define c11_userdata__as(T, self) (*( (T*)(self) ))
+
+#ifdef __cplusplus
+}
+
+namespace pkpy{
+    struct any: c11_userdata{
+        template<typename T>
+        any(T value){
+            c11_userdata__ctor(this, &value, sizeof(T));
+        }
+
+        any(){ }
+
+        template<typename T>
+        T as(){
+            return c11_userdata__as(T, this);
+        }
+    };
+}   // namespace pkpy
+#endif
\ No newline at end of file
diff --git a/include/pocketpy/common/any.hpp b/include/pocketpy/common/any.hpp
deleted file mode 100644
index 6fa09ee1..00000000
--- a/include/pocketpy/common/any.hpp
+++ /dev/null
@@ -1,113 +0,0 @@
-#pragma once
-
-#include "pocketpy/common/traits.hpp"
-
-#include <typeindex>
-#include <cassert>
-#include <utility>
-#include <cstdlib>
-#include <cstring>
-
-namespace pkpy {
-
-template <typename T>
-constexpr inline bool is_any_sso_v = is_pod_v<T> && sizeof(T) <= sizeof(void*);
-
-struct any {
-    struct vtable {
-        const std::type_index type;
-        void (*deleter)(void*);
-
-        template <typename T>
-        inline static vtable* get() {
-            static_assert(std::is_same_v<T, std::decay_t<T>>);
-            if constexpr(is_any_sso_v<T>) {
-                static vtable vt{typeid(T), nullptr};
-                return &vt;
-            } else {
-                static vtable vt{typeid(T), [](void* ptr) {
-                                     delete static_cast<T*>(ptr);
-                                 }};
-                return &vt;
-            }
-        }
-    };
-
-    void* data;
-    vtable* _vt;
-
-    any() : data(nullptr), _vt(nullptr) {}
-
-    explicit operator bool () const { return _vt != nullptr; }
-
-    template <typename T>
-    any(T&& value) {
-        using U = std::decay_t<T>;
-        static_assert(!std::is_same_v<U, any>, "any(const any&) is deleted");
-        static_assert(sizeof(U) == sizeof(T));
-        if constexpr(is_any_sso_v<U>) {
-            std::memcpy(&data, &value, sizeof(U));
-        } else {
-            data = new U(std::forward<T>(value));
-        }
-        _vt = vtable::get<U>();
-    }
-
-    any(any&& other) noexcept;
-    any& operator= (any&& other) noexcept;
-
-    const std::type_index type_id() const { return _vt ? _vt->type : typeid(void); }
-
-    any(const any& other) = delete;
-    any& operator= (const any& other) = delete;
-
-    ~any() {
-        if(_vt && _vt->deleter) _vt->deleter(data);
-    }
-
-    template <typename T>
-    T& _cast() const noexcept {
-        static_assert(std::is_same_v<T, std::decay_t<T>>);
-        if constexpr(is_any_sso_v<T>) {
-            return *((T*)(&data));
-        } else {
-            return *(static_cast<T*>(data));
-        }
-    }
-
-    template <typename T>
-    T& cast() const {
-        static_assert(std::is_same_v<T, std::decay_t<T>>);
-        if(type_id() != typeid(T)) __bad_any_cast(typeid(T), type_id());
-        return _cast<T>();
-    }
-
-    static void __bad_any_cast(const std::type_index expected, const std::type_index actual);
-};
-
-template <typename T>
-struct function;
-
-template <typename Ret, typename... Params>
-struct function<Ret(Params...)> {
-    any _impl;
-    Ret (*_wrapper)(const any&, Params...);
-
-    function() : _impl(), _wrapper(nullptr) {}
-
-    explicit operator bool () const { return _wrapper != nullptr; }
-
-    template <typename F>
-    function(F&& f) : _impl(std::forward<F>(f)) {
-        _wrapper = [](const any& impl, Params... params) -> Ret {
-            return impl._cast<std::decay_t<F>>()(std::forward<Params>(params)...);
-        };
-    }
-
-    Ret operator() (Params... params) const {
-        assert(_wrapper);
-        return _wrapper(_impl, std::forward<Params>(params)...);
-    }
-};
-
-}  // namespace pkpy
diff --git a/include/pocketpy/common/sstream.h b/include/pocketpy/common/sstream.h
index 282724de..6189e8ef 100644
--- a/include/pocketpy/common/sstream.h
+++ b/include/pocketpy/common/sstream.h
@@ -29,15 +29,15 @@ typedef struct pkpy_AnyStr {
     };
 } pkpy_AnyStr;
 
-inline pkpy_AnyStr pkpy_AnyStr__int(int x) { pkpy_AnyStr s; s.type = 1; s._int = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__i64(int64_t x) { pkpy_AnyStr s; s.type = 2; s._i64 = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__float(float x) { pkpy_AnyStr s; s.type = 3; s._float = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__double(double x) { pkpy_AnyStr s; s.type = 4; s._double = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__char(char x) { pkpy_AnyStr s; s.type = 5; s._char = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__str(const pkpy_Str* x) { pkpy_AnyStr s; s.type = 6; s._str = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__sv(c11_string x) { pkpy_AnyStr s; s.type = 7; s._sv = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__cstr(const char* x) { pkpy_AnyStr s; s.type = 8; s._cstr = x; return s; }
-inline pkpy_AnyStr pkpy_AnyStr__ptr(void* x) { pkpy_AnyStr s; s.type = 9; s._ptr = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__int(int x) { pkpy_AnyStr s; s.type = 1; s._int = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__i64(int64_t x) { pkpy_AnyStr s; s.type = 2; s._i64 = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__float(float x) { pkpy_AnyStr s; s.type = 3; s._float = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__double(double x) { pkpy_AnyStr s; s.type = 4; s._double = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__char(char x) { pkpy_AnyStr s; s.type = 5; s._char = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__str(const pkpy_Str* x) { pkpy_AnyStr s; s.type = 6; s._str = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__sv(c11_string x) { pkpy_AnyStr s; s.type = 7; s._sv = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__cstr(const char* x) { pkpy_AnyStr s; s.type = 8; s._cstr = x; return s; }
+PK_INLINE pkpy_AnyStr pkpy_AnyStr__ptr(void* x) { pkpy_AnyStr s; s.type = 9; s._ptr = x; return s; }
 
 void pkpy_SStream__ctor(pkpy_SStream* self);
 void pkpy_SStream__dtor(pkpy_SStream* self);
diff --git a/include/pocketpy/common/str.h b/include/pocketpy/common/str.h
index 9469fafc..c09be739 100644
--- a/include/pocketpy/common/str.h
+++ b/include/pocketpy/common/str.h
@@ -5,7 +5,9 @@ extern "C" {
 #endif
 
 #include <stdbool.h>
+
 #include "pocketpy/common/vector.h"
+#include "pocketpy/common/utils.h"
 
 /* string_view */
 typedef struct c11_string{
@@ -23,7 +25,7 @@ typedef struct pkpy_Str{
     };
 } pkpy_Str;
 
-inline const char* pkpy_Str__data(const pkpy_Str* self){
+PK_INLINE const char* pkpy_Str__data(const pkpy_Str* self){
     return self->is_sso ? self->_inlined : self->_ptr;
 }
 
diff --git a/include/pocketpy/common/utils.h b/include/pocketpy/common/utils.h
index d395c654..f11604da 100644
--- a/include/pocketpy/common/utils.h
+++ b/include/pocketpy/common/utils.h
@@ -4,6 +4,12 @@
 extern "C" {
 #endif
 
+#ifdef __cplusplus
+#define PK_INLINE inline
+#else
+#define PK_INLINE static inline
+#endif
+
 #define PK_REGION(name) 1
 
 #define PK_SLICE_LOOP(i, start, stop, step) for(int i = start; step > 0 ? i < stop : i > stop; i += step)
diff --git a/include/pocketpy/interpreter/vm.hpp b/include/pocketpy/interpreter/vm.hpp
index 1c2ec125..cb5276f6 100644
--- a/include/pocketpy/interpreter/vm.hpp
+++ b/include/pocketpy/interpreter/vm.hpp
@@ -9,6 +9,8 @@
 #include "pocketpy/interpreter/frame.hpp"
 #include "pocketpy/interpreter/profiler.hpp"
 
+#include <typeindex>
+
 namespace pkpy {
 
 /* Stack manipulation macros */
diff --git a/include/pocketpy/objects/codeobject.hpp b/include/pocketpy/objects/codeobject.hpp
index baefd679..d9afc2c9 100644
--- a/include/pocketpy/objects/codeobject.hpp
+++ b/include/pocketpy/objects/codeobject.hpp
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "pocketpy/common/any.hpp"
+#include "pocketpy/common/any.h"
 #include "pocketpy/objects/tuplelist.hpp"
 #include "pocketpy/objects/namedict.hpp"
 #include "pocketpy/objects/sourcedata.hpp"
@@ -171,10 +171,12 @@ struct Function {
 };
 
 template <typename T>
-T& lambda_get_userdata(PyVar* p) {
+T lambda_get_userdata(PyVar* p) {
     static_assert(std::is_same_v<T, std::decay_t<T>>);
+    static_assert(is_pod_v<T>);
     int offset = p[-1] != nullptr ? -1 : -2;
-    return p[offset].obj_get<NativeFunc>()._userdata.cast<T>();
+    NativeFunc& nf = p[offset].obj_get<NativeFunc>();
+    return nf._userdata.as<T>();
 }
 
 }  // namespace pkpy
diff --git a/src/common/any.c b/src/common/any.c
new file mode 100644
index 00000000..af22bd94
--- /dev/null
+++ b/src/common/any.c
@@ -0,0 +1,7 @@
+#include "pocketpy/common/any.h"
+
+#include <string.h>
+
+void c11_userdata__ctor(c11_userdata* self, void* ptr, int size){
+    memcpy(self, ptr, size);
+}
diff --git a/src/common/any.cpp b/src/common/any.cpp
deleted file mode 100644
index 6ec3636d..00000000
--- a/src/common/any.cpp
+++ /dev/null
@@ -1,26 +0,0 @@
-#include "pocketpy/common/any.hpp"
-#include "pocketpy/common/utils.h"
-
-#include <cstdio>
-
-namespace pkpy {
-
-void any::__bad_any_cast(const std::type_index expected, const std::type_index actual) {
-    PK_FATAL_ERROR("bad_any_cast: expected %s, got %s\n", expected.name(), actual.name())
-}
-
-any::any(any&& other) noexcept : data(other.data), _vt(other._vt) {
-    other.data = nullptr;
-    other._vt = nullptr;
-}
-
-any& any::operator= (any&& other) noexcept {
-    if(data) _vt->deleter(data);
-    data = other.data;
-    _vt = other._vt;
-    other.data = nullptr;
-    other._vt = nullptr;
-    return *this;
-}
-
-}  // namespace pkpy