PropertyWithValueExporter.h

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2011 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#pragma once
 
#include "MantidKernel/PropertyWithValue.h"
#include "MantidPythonInterface/core/Converters/ContainerDtype.h"
 
#ifndef Q_MOC_RUN
#include <boost/python/bases.hpp>
#include <boost/python/class.hpp>
#include <boost/python/return_by_value.hpp>
#include <boost/python/return_value_policy.hpp>
#endif
 
namespace {
 
// Call the dtype helper function
template <typename HeldType> std::string dtype(Mantid::Kernel::PropertyWithValue<HeldType> &self) {
  // Check for the special case of a string
  if constexpr (std::is_same<HeldType, std::string>::value) {
    std::stringstream ss;
    std::string val = self.value();
    ss << "S" << val.size();
    std::string ret_val = ss.str();
    return ret_val;
  }
 
  return Mantid::PythonInterface::Converters::dtype(self);
}
 
// getter and setter helper functions for `value` Python property export.
template <typename T> static T const &get_value(Mantid::Kernel::PropertyWithValue<T> const &self) {
  return self(); // forwards to operator()()
}
 
template <typename T> static void set_value(Mantid::Kernel::PropertyWithValue<T> &self, T const &v) {
  self = v; // forwards to operator=
}
 
} // namespace
 
namespace Mantid {
namespace PythonInterface {
 
template <typename HeldType, typename ValueReturnPolicy = boost::python::return_by_value>
struct PropertyWithValueExporter {
  static void define(const char *pythonClassName) {
    using namespace boost::python;
    using namespace Mantid::Kernel;
 
    class_<PropertyWithValue<HeldType>, bases<Property>, boost::noncopyable>(
        pythonClassName, init<std::string, HeldType, unsigned int>(
                             (arg("self"), arg("name"), arg("value"), arg("direction") = Direction::Input)))
        .add_property("value", make_function(&get_value<HeldType>, return_value_policy<ValueReturnPolicy>()),
                      &set_value<HeldType>)
        .def("dtype", &dtype<HeldType>, arg("self"));
  }
};
} // namespace PythonInterface
} // namespace Mantid