misc.h

Go to the documentation of this file.

/******************************************************************************
 Copyright (c) 2012-2016 Institut für Nachrichtentechnik, Universität Rostock
 Copyright (c) 2006-2012 Quality & Usability Lab
                         Deutsche Telekom Laboratories, TU Berlin
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
*******************************************************************************/
 
// https://AudioProcessingFramework.github.io/
 
 
#ifndef APF_MISC_H
#define APF_MISC_H
 
#include <utility>  // for std::forward
#include <type_traits>  // for std::is_base_of
 
namespace apf
{
 
template<typename Derived>
class CRTP
{
  public:
    Derived& derived()
    {
      static_assert(std::is_base_of<CRTP, Derived>::value
          , "Derived must be derived from CRTP (as the name suggests)!");
 
      return *static_cast<Derived*>(this);
    }
 
  protected:
     CRTP() = default;
    ~CRTP() = default;  
};
 
class NonCopyable
{
  protected:
     NonCopyable() = default;  
    ~NonCopyable() = default;  
 
  public:
 
    NonCopyable(const NonCopyable&) = delete;
    NonCopyable& operator=(const NonCopyable&) = delete;
 
 
    NonCopyable(NonCopyable&&) = default;
    NonCopyable& operator=(NonCopyable&&) = default;
};
 
template<typename T>
class BlockParameter
{
  public:
    template<typename... Args>
    explicit BlockParameter(Args&&... args)
      : _current(args...)
      , _old(std::forward<Args>(args)...)
    {}
 
    template<typename Arg>
    T& operator=(Arg&& arg)
    {
#ifndef NDEBUG
      ++_assignments;
#endif
 
      _old = std::move(_current);
      return _current = std::forward<Arg>(arg);
    }
 
    const T& get() const { return _current; }  
    const T& old() const { return _old; }  
 
    operator const T&() const { return this->get(); }
 
    bool changed() const { return this->get() != this->old(); }
 
    BlockParameter& operator+=(const T& rhs) { _current += rhs; return *this; }
    BlockParameter& operator-=(const T& rhs) { _current -= rhs; return *this; }
    BlockParameter& operator*=(const T& rhs) { _current *= rhs; return *this; }
    BlockParameter& operator/=(const T& rhs) { _current /= rhs; return *this; }
    BlockParameter& operator%=(const T& rhs) { _current %= rhs; return *this; }
    BlockParameter& operator&=(const T& rhs) { _current &= rhs; return *this; }
    BlockParameter& operator|=(const T& rhs) { _current |= rhs; return *this; }
    BlockParameter& operator<<=(const T& rhs){ _current <<= rhs; return *this; }
    BlockParameter& operator>>=(const T& rhs){ _current >>= rhs; return *this; }
 
    BlockParameter& operator++() { ++_current; return *this; }
    BlockParameter& operator--() { --_current; return *this; }
    T operator++(int) { return _current++; }
    T operator--(int) { return _current--; }
 
  private:
    class both_proxy
    {
      public:
        explicit both_proxy(const BlockParameter& param) : _p(param) {}
 
#define APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(opstring) \
        friend bool operator opstring(const both_proxy& lhs, const T& rhs) { \
          return lhs._p.get() opstring rhs && lhs._p.old() opstring rhs; } \
        friend bool operator opstring(const T& lhs, const both_proxy& rhs) { \
          return lhs opstring rhs._p.get() && lhs opstring rhs._p.old(); }
 
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(==)
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(!=)
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(<)
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(>)
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(<=)
        APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS(>=)
#undef APF_BLOCKPARAMETER_BOTH_PROXY_OPERATORS
 
      private:
        const BlockParameter& _p;
    };
 
  public:
 
    both_proxy both() const { return both_proxy(*this); }
 
#ifndef NDEBUG
    bool no_multiple_assignments() const
    {
      auto result = (_assignments <= 1);
      _assignments = 0;
      return result;
    }
 
    bool exactly_one_assignment() const
    {
      auto result = (_assignments == 1);
      _assignments = 0;
      return result;
    }
#endif
 
  private:
    T _current, _old;
 
#ifndef NDEBUG
    mutable int _assignments = 0;
#endif
};
 
} // namespace apf
 
#endif