added more math operators for value_t types

python.cc

@@ -63,16 +63,7 @@ void init_python()
   Py_Initialize();
   python_interpretor = new python_support;
 
-#if 1
-  boost::python::detail::init_module("ledger", &init_module);
-#else
-  object m_obj(python_interpretor->main_module);
-  scope  current_module(m_obj);
-
-  python_interpretor->main_namespace.attr("bar") = 10;
-
-  handle_exception(init_module_main);
-#endif
+  detail::init_module("ledger", &init_module);
 }
 
 } // namespace ledger

value.cc

@@ -642,6 +642,26 @@ void export_value()
     .def(self / other<amount_t>())
     .def(self / int())
 
+    .def(other<balance_pair_t>() + self)
+    .def(other<balance_t>() + self)
+    .def(other<amount_t>() + self)
+    .def(int() + self)
+
+    .def(other<balance_pair_t>() - self)
+    .def(other<balance_t>() - self)
+    .def(other<amount_t>() - self)
+    .def(int() - self)
+
+    .def(other<balance_pair_t>() * self)
+    .def(other<balance_t>() * self)
+    .def(other<amount_t>() * self)
+    .def(int() * self)
+
+    .def(other<balance_pair_t>() / self)
+    .def(other<balance_t>() / self)
+    .def(other<amount_t>() / self)
+    .def(int() / self)
+
     .def(self += self)
     .def(self += other<balance_pair_t>())
     .def(self += other<balance_t>())

value.h

@@ -249,6 +249,23 @@ class value_t
   value_t cost() const;
 };
 
+template <typename T>
+value_t operator+(const T& value, const value_t& obj) {
+  return value_t(value) + obj;
+}
+template <typename T>
+value_t operator-(const T& value, const value_t& obj) {
+  return value_t(value) - obj;
+}
+template <typename T>
+value_t operator*(const T& value, const value_t& obj) {
+  return value_t(value) * obj;
+}
+template <typename T>
+value_t operator/(const T& value, const value_t& obj) {
+  return value_t(value) / obj;
+}
+
 template <typename T>
 value_t::operator T() const
 {