ext_example.cpp

#include "hphp/runtime/ext/extension.h"
#include "hphp/runtime/base/execution-context.h"
#include "hphp/runtime/vm/native-data.h"

class complex {
public:
  double real, img;
  complex() {}
  complex(double r, double i): real(r), img(i) {}
};

complex add(complex a, complex b) {
  complex r;
  r.real = a.real + b.real;
  r.img = a.img + b.img;
  return r;
}

namespace HPHP {

class wrap_complex {
public:
  complex* m_ptr;
  ~wrap_complex() {
    delete m_ptr;
    m_ptr = nullptr;
  } 
};

void HHVM_METHOD(wrap_complex, __construct, double r, double i) {
  auto data = Native::data<wrap_complex>(this_);
  data->m_ptr = new complex(r, i);
}

void HHVM_FUNCTION(print_complex, const Object& c) {
  auto data = Native::data<wrap_complex>(c);
  printf("%lf %lf\n", data->m_ptr->real, data->m_ptr->img);
}

Object HHVM_FUNCTION(add, const Object& a, const Object &b) {
  auto cls = Unit::lookupClass(HPHP::makeStaticString("wrap_complex"));
  Object ret{cls};
  auto wa = HPHP::Native::data<wrap_complex>(a)->m_ptr;
  auto wb = HPHP::Native::data<wrap_complex>(b)->m_ptr;
  auto result = add(*wa, *wb);
  auto wrap_result = HPHP::Native::data<wrap_complex>(ret);
  wrap_result->m_ptr = new complex((const complex &) result);
  return ret;
}

class EXAMPLEExtension : public Extension {
public:
  EXAMPLEExtension(): Extension("example", "1.0") {}

  void moduleInit() override {
    HHVM_MALIAS(complex, __construct, wrap_complex, __construct);
    HHVM_FE(print_complex);
    HHVM_FE(add);
    Native::registerNativeDataInfo<wrap_complex>(makeStaticString("wrap_complex"));
    loadSystemlib();
  }
} s_example_extension;

HHVM_GET_MODULE(example);

}

ext_example.php

<?hh

<<__NativeData("wrap_complex")>>
class complex {
  <<__Native>>
  public function __construct(double $real, double $img): void;
}

<<__Native>>
function print_complex(complex $c): void;

<<__Native>>
function add(complex $a, complex $b): complex;

test.php

<?php

$c = new complex(2, 3);
$d = new complex(2, 3);
$a = add($c, $d);
print_complex($a);

?>