Is that possible to store the proxy object inside another object of the same proxy type?

[zhiyongww]

Hey, my code failed to compile, I'm not able to figure it out through error messages.

Could you please help to take a look? thanks.

#include <iostream>
#include "proxy.h"

PRO_DEF_MEM_DISPATCH(MemGetDescription, getDescription);
PRO_DEF_MEM_DISPATCH(MemGetCost, getCost);
struct Beverage : pro::facade_builder
    ::add_convention<MemGetDescription, std::string()>
    ::add_convention<MemGetCost, double()>
    ::support_copy<pro::constraint_level::nontrivial>
    ::build {
};


class Espresso {
public:
  std::string getDescription() {
    return description_;
  }

  double getCost() {
    return cost_;
  }

private:
  const std::string description_ = "Espresso";
  const double cost_ = 1.99;
};

class Mocha {
public:
  explicit Mocha(pro::proxy<Beverage> beverage) : beverage_(std::move(beverage)) {
  }

  std::string getDescription() {
    return beverage_->getDescription() + ", Mocha";
  }

  double getCost() {
    return beverage_->getCost() + 0.20;
  }
private:
  pro::proxy<Beverage> beverage_;
};

void test_decorator() {
  pro::proxy<Beverage> beverage = pro::make_proxy<Beverage, Espresso>();
  pro::proxy<Beverage> b2 = pro::make_proxy<Beverage, Mocha>(beverage);
  std::cout << beverage->getDescription() << " $" << beverage->getCost() << std::endl;
}

[mingxwa]

Hi @zhiyongww, sorry for the delayed response. This is a known issue in the latest release. While the diagnostics got improved, Proxy won't diagnose convertibility on the constructors. As a result, if proxy is the only parameter of a constructor (like Mocha::Mocha(proxy) in your case), it will be shadowed by the constructor of proxy (proxy::proxy(P&&)).

This issue has been fixed on the main branch (see #278), and will be included in the next release. Please let me know if you have any further questions.

[zhiyongww]

Thank you so much, using the latest proxy library fixed my issue. I thought I use the library in a wrong way.