How to print boost::any to a stream?

by

You could use boost::spirit::hold_any instead. It’s defined here:

#include <boost/spirit/home/support/detail/hold_any.hpp>

and is fully compatible with boost::any. This class has two differences if compared to boost::any:

  • it utilizes the small object optimization idiom and a couple of other optimization tricks, making spirit::hold_any smaller and faster than boost::any
  • it has the streaming operators (operator<<() and operator>>()) defined, allowing to input and output a spirit::hold_any seemlessly.

The only limitation is that you can’t input into an empty spirit::hold_any, but it needs to be holding a (possibly default constructed) instance of the type which is expected from the input.

More Related Contents:

  1. How to link C++ program with Boost using CMake
  2. undefined reference to boost::system::system_category() when compiling
  3. Cross-platform way to get line number of an INI file where given option was found
  4. How can I decode the boost library naming?
  5. boost::spirit::qi duplicate parsing on the output
  6. How can I compose output streams, so output goes multiple places at once?
  7. Which Boost libraries are header-only?
  8. Which Boost features overlap with C++11?
  9. How to link to dynamic boost libs?
  10. Is there a way to test whether a C++ class has a default constructor (other than compiler-provided type traits)?
  11. boost::flat_map and its performance compared to map and unordered_map
  12. CMake is not finding Boost
  13. Boost ASIO streambuf
  14. how provide a vertex_index property for my graph
  15. C++ N nested vectors at runtime
  16. Best way for interprocess communication in C++
  17. C++ & Boost: encode/decode UTF-8
  18. Why does nvcc fails to compile a CUDA file with boost::spirit?
  19. linker error while linking boost log tutorial (undefined references)
  20. undefined behaviour somewhere in boost::spirit::qi::phrase_parse
  21. Possible causes for Boost not being found by CMake in certain situations?
  22. C++ Boost ASIO simple periodic timer?
  23. Creating Library with backward compatible ABI that uses Boost
  24. QTableView printing
  25. Constraining the existing Boost.Spirit real_parser (with a policy)
  26. want to efficiently overcome mismatch between key types in a map in Boost.Interprocess shared memory
  27. C++ Serialization Performance
  28. Calculate mean and standard deviation from a vector of samples in C++ using Boost
  29. How to enable_shared_from_this of both parent and derived
  30. Conversion from boost::shared_ptr to std::shared_ptr?

Leave a Comment