Overloading operator

by

You have a problem with a “non-deducible context” in this operator

template<typename T>
inline std::ostream& operator<< (std::ostream &out,
                                 const typename classA<T>::classB &b)
{
  return out;
}

The compiler cannot figure out what values of T will result in a classB that matches the parameter you want to pass. So this template is not considered!

In C++11 mode, the compiler then goes on to find a close match from the standard library

operator<<(std::basic_ostream<_CharT, _Traits>&&, const _Tp&)

where it can match _Tp to just about any type, including classA<T>::classB, but notes that the first parameter doesn’t match.

More Related Contents:

  1. Reading garbage instead of segfault for non-existant memory locations
  2. Why data cast is not working here in c++?
  3. Is Meyers’ implementation of the Singleton pattern thread safe?
  4. Difference of keywords ‘typename’ and ‘class’ in templates?
  5. Is ncurses available for windows? [closed]
  6. How to change mode from c++98 mode in Dev-C++ to a mode that supports C++0x (range based for)?
  7. How to create a thread pool using boost in C++?
  8. How to get the MD5 hash of a file in C++? [closed]
  9. How to get available memory C++/g++?
  10. Understanding std::hardware_destructive_interference_size and std::hardware_constructive_interference_size
  11. std::array vs array performance
  12. Why use functors over functions?
  13. Access variable value using string representing variable’s name in C++ [duplicate]
  14. boost spirit semantic action parameters
  15. What’s faster, iterating an STL vector with vector::iterator or with at()?
  16. When to use const and const reference in function args?
  17. Does delete on a pointer to a subclass call the base class destructor?
  18. Standard-layout and tail padding
  19. Assertion failed (size.width>0 && size.height>0)
  20. How to solve Memory Fragmentation
  21. If I do a `typedef` in C or C++, when should I add `_t` at the end of typedef’ed type? [duplicate]
  22. Better shading on BW display while rendering filled surfaces
  23. How to use profile guided optimizations in g++?
  24. Performance of qsort vs std::sort?
  25. How does C++ STL unordered_map resolve collisions?
  26. C++ uninitialized local variable
  27. error: ‘INT32_MAX’ was not declared in this scope
  28. Why would I std::move an std::shared_ptr?
  29. difference between pointer to an array and pointer to the first element of an array
  30. Wrapping FILE* with custom std::ostream

Leave a Comment