ClassTimer.hpp

/*
 * (c) Copyright 2020 CORSIKA Project, corsika-project@lists.kit.edu
 *
 * This software is distributed under the terms of the GNU General Public
 * Licence version 3 (GPL Version 3). See file LICENSE for a full version of
 * the license.
 */

// Another possibility:
// https://en.wikibooks.org/wiki/More_C%2B%2B_Idioms/Execute-Around_Pointer
// for a more global approach
//
// In this case here only a single function is measured via member function pointer.

#pragma once

#include <chrono>
#include <utility>

#include <corsika/framework/analytics/Timer.hpp>

namespace corsika {

  template <class TClass, typename TTimer>
  class ClassTimerImpl : public TTimer {
    static_assert(
        is_timer_v<TTimer>,
        "TTimer is not a timer!"); // Better
                                   // https://en.cppreference.com/w/cpp/language/constraints
                                   // but not available in C++17

  protected:
    TClass& obj_;

  public:
    ClassTimerImpl(TClass& obj)
        : obj_(obj){};
  };


  template <typename TClassFunc, TClassFunc TFunc,
            typename TTimer =
                Timer<std::chrono::high_resolution_clock, std::chrono::microseconds>>
  class ClassTimer;


  template <typename TClass, typename TRet, typename... TArgs,
            TRet (TClass::*TFuncPtr)(TArgs...), typename TTimer>
  class ClassTimer<TRet (TClass::*)(TArgs...), TFuncPtr, TTimer>
      : public ClassTimerImpl<TClass, TTimer> {
  private:
  public:
    ClassTimer(TClass& obj);


    TRet call(TArgs... args);
  };

  template <typename TClass, typename... TArgs, void (TClass::*TFuncPtr)(TArgs...),
            typename TTimer>
  class ClassTimer<void (TClass::*)(TArgs...), TFuncPtr, TTimer>
      : public ClassTimerImpl<TClass, TTimer> {
  public:
    ClassTimer(TClass& obj);

    void call(TArgs... args);
  };

  template <typename TClass, typename TRet, typename... TArgs,
            TRet (TClass::*TFuncPtr)(TArgs...) const, typename TTimer>
  class ClassTimer<TRet (TClass::*)(TArgs...) const, TFuncPtr, TTimer>
      : public ClassTimerImpl<TClass, TTimer> {
  public:
    ClassTimer(TClass& obj);

    TRet call(TArgs... args);
  };

  template <typename TClass, typename... TArgs, void (TClass::*TFuncPtr)(TArgs...) const,
            typename TTimer>
  class ClassTimer<void (TClass::*)(TArgs...) const, TFuncPtr, TTimer>
      : public ClassTimerImpl<TClass, TTimer> {
  public:
    ClassTimer(TClass& obj);

    void call(TArgs... args);
  };

} // namespace corsika

#include <corsika/detail/framework/analytics/ClassTimer.inl>