On Wed, Jan 30, 2013 at 7:27 PM, Tal Zion <talzion12@gmail.com> wrote:
The library defines a templated operator<< that is enabled (by Boost.EnableIf) for all types that have a const_iterator typedef, or evaluate to true in boost::fusion::is_sequence<T> and are not already ostreamable.
boost::iterator_range already defines operator<< and so the library will "back down" and let iterator_range do its job. The library tries not to interfere with other objects. If another object says it can be outputted to an ostream, the library "believes" it. By using this philosophy, the library prevents any ambiguity in operator<<.
But to answer your question, the library is completely generic and it does support arbitrary ranges.
Here are some code snippets that show how the library captures a range:
[snip] I'm not familiar with has_left_shift behavior but from the look of it it seems that it checks for availability of operator<< with a particular signature. If so, the is_ostreamable check is unreliable because there may be a suitable operator<< to be found by ADL or otherwise which does not match the signature. Anyway, I feel very uncomfortable about defining such blanket operators because it can interfere with user's code and intentions. I would prefer the manipulator-based approach.