For nested templates, when did `>>` become standard C++ (instead of `> >`)?

by

Templates closed with nested >> are officially supported by the upcoming standard C++0x (now C++11). Previously you would need the space, or a compiler that went the extra mile for you (and did things not indicated by the standard).

The issue stems from the fact that >> in C is the right-shift operator, which is a single lexical token, which conflicts with the two separate > tokens that would be needed during the parsing stage in a classically-constructed C++ compiler (and only in the case of templates, not when it actually is a right-shift). In other words, the >>, if allowed to close nested templates, is lexically ambiguous, but this can be (and is being) addressed by extra sophistication during parsing (which in modern C++ is really nothing new).

More Related Contents:

  1. Why can templates only be implemented in the header file?
  2. Difference of keywords ‘typename’ and ‘class’ in templates?
  3. C++ templates that accept only certain types
  4. How to easily map c++ enums to strings
  5. How to declare a templated struct/class as a friend?
  6. Is it possible to emulate template?
  7. templates: parent class member variables not visible in inherited class
  8. How to initialize std::array elegantly if T is not default constructible?
  9. Template issue causes linker error (C++) [duplicate]
  10. Template tuple – calling a function on each element
  11. Calling a function for each variadic template argument and an array
  12. C++ templates, undefined reference
  13. Workaround for template argument deduction in non-deduced context
  14. Are C++ Templates just Macros in disguise?
  15. Disambiguate overloaded member function pointer being passed as template parameter
  16. How to correctly initialize member variable of template type?
  17. C++ parameter pack, constrained to have instances of a single type?
  18. “Undefined symbols” linker error with simple template class
  19. using class name in a class template without template parameters
  20. Template instantiation details of GCC and MS compilers
  21. How can I expand call to variadic template base classes?
  22. Template Metaprogramming – Difference Between Using Enum Hack and Static Const
  23. How does C++ link template instances
  24. templated typedef?
  25. std::enable_if : parameter vs template parameter
  26. Templates: template function not playing well with class’s template member function [duplicate]
  27. Is there a way to write make_unique() in VS2012?
  28. Dependent scope and nested templates
  29. Concatenate compile-time strings in a template at compile time?
  30. using extern template (C++11) to avoid instantiation

Leave a Comment