Singleton-impl.hpp

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#ifndef DART_COMMON_DETAIL_SINGLETON_HPP_
#define DART_COMMON_DETAIL_SINGLETON_HPP_
 
#include "dart/common/Singleton.hpp"
 
#include <utility>
 
namespace dart {
namespace common {
 
//==============================================================================
template <typename T>
T* Singleton<T>::mInstance = nullptr;
 
//==============================================================================
template <typename T>
template <typename... Args>
T& Singleton<T>::getSingleton(Args... _args)
{
  // http://stackoverflow.com/questions/1008019/c-singleton-design-pattern
 
  // Guaranteed to be destroyed and instantiated on first use.
  if (mInstance == nullptr)
  {
    static T instance(std::forward<Args>(_args)...);
    mInstance = &instance;
  }
 
  return *mInstance;
}
 
//==============================================================================
template <typename T>
template <typename... Args>
T* Singleton<T>::getSingletonPtr(Args... _args)
{
  return &getSingleton(std::forward<Args>(_args)...);
}
 
} // namespace common
} // namespace dart
 
#endif // DART_COMMON_DETAIL_SINGLETON_HPP_