JResolve.hh

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#ifndef __JLANG__JRESOLVE__
#define __JLANG__JRESOLVE__
 
#include <type_traits>
 
/**
 * \author mdejong
 */
 
namespace JLANG {}
namespace JPP { using namespace JLANG; }
 
namespace JLANG {
 
  /**
   * Test existence of class T.
   */
  template<class T>
  class JResolve
  {
    template<class U>   static auto exists(U*)  -> decltype(sizeof(U) >= 0);
    template<typename>  static auto exists(...) -> std::false_type;
 
  public:
    static const bool value = std::is_same<bool, decltype(exists<T>(0))>::value;   //!< true if an implementation of class T exists; else false
  };
}
 
#endif