diff --git a/build.sh b/build.sh
index ee7b0dd..9c6ebb5 100755
--- a/build.sh
+++ b/build.sh
@@ -1,8 +1,12 @@
-clang src/main.c -g -o ./bin/slime --std=c99 || exit 1
+SCRIPTPATH="$( cd "$(dirname "$0")" ; pwd -P )"
+pushd $SCRIPTPATH > /dev/null
+
+clang++ src/main.cpp -g -o ./bin/slime --std=c++17 || exit 1
 
 echo ""
 echo "--- Output Start ---"
-pushd bin
-./slime
-popd
+pushd bin > /dev/null
+./slime --run-tests
+popd > /dev/null
 echo "--- Output End ---"
+popd > /dev/null
diff --git a/src/defines.cpp b/src/defines.cpp
index 4230ed2..cb922ad 100644
--- a/src/defines.cpp
+++ b/src/defines.cpp
@@ -9,11 +9,12 @@ constexpr bool is_debug_build = false;
 
 #define if_debug if constexpr (is_debug_build)
 
-// #ifdef _MSC_VER
+#ifdef _MSC_VER
 # define debug_break() if_debug __debugbreak()
-// #else
-// # define debug_break() if_debug __builtin_trap()
-// #endif
+#else
+# include <signal.h>
+# define debug_break() if_debug raise(SIGTRAP)
+#endif
 
 #define assert(cond)                                                    \
     if_debug {                                                          \
diff --git a/src/error.cpp b/src/error.cpp
index 5141eb3..80e60ca 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -9,9 +9,8 @@ proc delete_error() -> void {
 
 proc create_error(Error_Type type, Source_Code_Location* location) -> void {
     delete_error();
-    if_debug {
-        debug_break();
-    }
+    debug_break();
+
     error = new(Error);
     error->type = type;
     error->location = location;
diff --git a/src/eval.cpp b/src/eval.cpp
index fd0481b..8b5f00c 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -388,8 +388,7 @@ proc eval_expr(Lisp_Object* node, Environment* env) -> Lisp_Object* {
 
         // check for c function
         if (lispOperator->type == Lisp_Object_Type::CFunction) {
-            Lisp_Object* result = lispOperator->value.lambdaWrapper->function(arguments, env);
-            // Lisp_Object* result = (*lispOperator->value.lambdaWrapper)(arguments, env);
+            Lisp_Object* result = lispOperator->value.cFunction->function(arguments, env);
             return result;
         }
 
diff --git a/src/main.cpp b/src/main.cpp
index 88d52b5..66775d7 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -2,13 +2,17 @@
 
 int main(int argc, char* argv[]) {
     if (argc > 1) {
+        if (Slime::string_equal(argv[1], "--run-tests")) {
+            Slime::run_all_tests();
+            return 0;
+        }
+
         Slime::interprete_file(argv[1]);
         if (Slime::error) {
             Slime::log_error();
             return 1;
         }
     } else {
-        Slime::run_all_tests();
         Slime::interprete_stdin();
     }
 }
diff --git a/src/memory.cpp b/src/memory.cpp
index ca2de6a..6b48beb 100644
--- a/src/memory.cpp
+++ b/src/memory.cpp
@@ -154,10 +154,12 @@ namespace Memory {
             Memory::create_string(keyword));
     }
 
-    proc create_lisp_object_cfunction(TransientFunction<Lisp_Object* (Lisp_Object*, Environment*)> function) -> Lisp_Object* {
+    proc create_lisp_object_cfunction(std::function<Lisp_Object* (Lisp_Object*, Environment*)> function) -> Lisp_Object* {
         Lisp_Object* node = create_lisp_object();
         node->type = Lisp_Object_Type::CFunction;
-        node->value.lambdaWrapper = new Lambda_Wrapper(function);
+        // node->value.lambdaWrapper = new Lambda_Wrapper(function);
+        node->value.cFunction = new(cFunction);
+        node->value.cFunction->function = function;
         return node;
     }
 
diff --git a/src/slime.h b/src/slime.h
index d8eaae7..21baf86 100644
--- a/src/slime.h
+++ b/src/slime.h
@@ -3,6 +3,7 @@
 #define _CRT_SECURE_NO_DEPRECATE
 #include <stdio.h>
 #include <string.h>
+#include <cmath>
 // #include <type_traits>
 #include <functional>
 
diff --git a/src/structs.cpp b/src/structs.cpp
index 02e1cc5..aafa52c 100644
--- a/src/structs.cpp
+++ b/src/structs.cpp
@@ -7,56 +7,6 @@ define_array_list(String*, String);
 define_array_list(int, Int);
 define_array_list(void*, Void_Ptr);
 
-// -----------------------------
-//   <crazy lambda wrapper>
-// -----------------------------
-// SOURCE: http://brnz.org/hbr/?p=1767
-template<typename>
-struct TransientFunction; // intentionally not defined
-
-template<typename R, typename ...Args>
-struct TransientFunction<R(Args...)>
-{
-    using Dispatcher = R(*)(void*, Args...);
-
-    Dispatcher m_Dispatcher; // A pointer to the static function that will call the
-    // wrapped invokable object
-    void* m_Target;          // A pointer to the invokable object
-
-    // Dispatch() is instantiated by the TransientFunction constructor,
-    // which will store a pointer to the function in m_Dispatcher.
-    template<typename S>
-    static R Dispatch(void* target, Args... args) {
-        return (*(S*)target)(args...);
-    }
-
-    template<typename T>
-    TransientFunction(T&& target)
-        : m_Dispatcher(&Dispatch<typename std::decay<T>::type>)
-        , m_Target(&target)
-        {}
-
-    // Specialize for reference-to-function, to ensure that a valid pointer is
-    // stored.
-    using TargetFunctionRef = R(Args...);
-    TransientFunction(TargetFunctionRef target)
-        : m_Dispatcher(Dispatch<TargetFunctionRef>)
-        {
-            static_assert(sizeof(void*) == sizeof target,
-                          "It will not be possible to pass functions by reference on this platform. "
-                          "Please use explicit function pointers i.e. foo(target) -> foo(&target)");
-            m_Target = (void*)target;
-        }
-
-    R operator()(Args... args) const {
-        return m_Dispatcher(m_Target, args...);
-    }
-};
-// -----------------------------
-//   </crazy lambda wrapper>
-// -----------------------------
-
-
 enum struct Lisp_Object_Type {
     Nil,
     T,
@@ -157,10 +107,8 @@ struct Function {
     Environment* parent_environment; // we are doing closures now!!
 };
 
-
-struct Lambda_Wrapper {
-    Lambda_Wrapper(TransientFunction<Lisp_Object* (Lisp_Object*, Environment*)> f) : function(f) {}
-    TransientFunction<Lisp_Object* (Lisp_Object*, Environment*)> function;
+struct cFunction {
+    std::function<Lisp_Object* (Lisp_Object*, Environment*)> function;
 };
 
 struct Lisp_Object {
@@ -173,7 +121,7 @@ struct Lisp_Object {
         String*   string;
         Pair*     pair;
         Function* function;
-        Lambda_Wrapper* lambdaWrapper;
+        cFunction* cFunction;
     } value;
 };