Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Header <boost/test/tools/detail/per_element_manip.hpp>

Per element comparison manipulator implementation.

namespace boost {
  namespace test_tools {
    struct per_element;
    unit_test::lazy_ostream & 
    operator<<(unit_test::lazy_ostream & o, per_element);
    std::ostream & operator<<(std::ostream & o, per_element);
  }
}