resolvers.hpp

/*
  ANCH Framework: ANother C++ Hack is a C++ framework based on C++11 standard
  Copyright (C) 2012 Vincent Lachenal
 
  This file is part of ANCH Framework.
 
  ANCH Framework is free software: you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.
 
  ANCH Framework is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public License
  along with ANCH Framework.  If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
 
#include <map>
#include <functional>
#include <string>
#include <optional>
#include <set>
 
#include "conf/configuration.hpp"
 
#include "singleton.hpp"
 
 
namespace anch::conf {

  using Resolver = std::function<std::optional<std::string>(const std::string& /*name*/,
                                                            const std::optional<std::string>& /*args*/)>;

  class Resolvers: public anch::Singleton<Resolvers> {
    friend anch::conf::Configuration;
    friend anch::Singleton<Resolvers>;
 
    // Attributes +
  public:
    static const std::string ENV;

    static const std::string CONF;

    static const std::string ARG;
 
  private:
    std::map<std::string, Resolver> _registry;

    std::set<std::string> _protected;
    // Attributes -
 
    // Constructors +
  private:
    Resolvers();
 
  public:
    Resolvers(const Resolvers& resolvers) = delete;

    Resolvers(Resolvers&& resolvers) = delete;
    // Constructors -
 
    // Destructor +
  private:
    virtual ~Resolvers();
    // Destructor -
 
    // Methods +
  public:
    Resolvers& registerResolver(Resolver resolver, const std::string& key);

    Resolver getResolver(const std::string& key) const;

    bool hasResolver(const std::string& key) const;
    // Methods -
 
  };
 
}
 
#include "conf/impl/resolvers.hpp"