id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
11625	BOOST_TEST( ..., per_element() ) erroneously requires collections are comparable	Tony Lewis <tonyelewis@…>	Raffi Enficiaud	"Thanks for the new BOOST_TEST() and per_element() tools, which look very useful.

Unfortunately, I'm having trouble with comparing collections that aren't themselves comparable but have comparable elements.

As I understand [http://www.boost.org/libs/test/doc/html/boost_test/testing_tools/extended_comparison/collections.html#boost_test.testing_tools.extended_comparison.collections.requirements the requirements documentation] for the BOOST_TEST / per_element() tools, they should only require that the two collections' ''elements'' are comparable, not necessarily the two collections themselves. I think this approach makes a lot of sense.

However, when I try to compile the following under either `g++ -std=c++11` or `clang -std=c++11 -stdlib=libc++`, the compilers complain that collections aren't comparable :

{{{#!cpp
#define BOOST_TEST_MODULE comp_by_elem_mod

#include <boost/test/included/unit_test.hpp>

#include <iterator>
#include <vector>

struct my_class final {
	std::vector<int> the_ints = { 1, 2, 3 };

	using const_iterator = std::vector<int>::const_iterator;

	const_iterator begin() const {
		return std::begin( the_ints );
	}
	const_iterator end() const {
		return std::end( the_ints );
	}
};

BOOST_AUTO_TEST_CASE( comp_by_elem ) {
	const my_class         a{};
	const std::vector<int> b = { 1, 2, 3 };
	BOOST_TEST( a == b, ::boost::test_tools::per_element() );
}

}}}

I'll attach compiler errors.

Many thanks."	Bugs	closed	To Be Determined	test	Boost 1.60.0	Problem	invalid	BOOST_TEST,per_element,collections,comparable,element,range,equality