Add 'xo-jit/' from commit '855887df71'

git-subtree-dir: xo-jit
git-subtree-mainline: 35555df976
git-subtree-split: 855887df71

xo-jit/example/ex_cpp/ex_cpp.cpp

@@ -0,0 +1,40 @@
+struct env_type;
+
+struct closure_type {
+    double (*fnptr)(env_type * env, double x);
+    env_type * envptr;
+};
+
+double
+sqrt(double x) {
+    return x/100;
+}
+
+double
+wrap_sqrt(env_type * env, double x) {
+    return ::sqrt(x);
+}
+
+double twice(env_type * env, closure_type fnclosure, double x) {
+    double tmp1 = (*fnclosure.fnptr)(fnclosure.envptr, x);
+    double tmp2 = (*fnclosure.fnptr)(fnclosure.envptr, tmp1);
+
+    return tmp2;
+}
+
+closure_type make_some_closure()
+{
+    closure_type closure;
+    closure.fnptr = &wrap_sqrt;
+    closure.envptr = nullptr;
+
+    return closure;
+}
+
+int main() {
+    closure_type closure = make_some_closure();
+
+    double y = twice(nullptr, closure, 4.0);
+
+    //std::cout << "y=" << y << std::endl;
+}