id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12645	error: no match for call to ‘(const hash) (const boost::recursive_variant_&)’	mike.gresens@…	Antony Polukhin	"Since boost 1.62 the recursive variant is not able to find the hash function.[[BR]]
Same for boost 1.63 beta.[[BR]]
Compiler stops with error: no match for call to ‘(const hash) (const boost::recursive_variant_&)’

code:
{{{
#include <boost/variant.hpp>
#include <unordered_set>

struct hash;

using int_t = int;

template <typename T>
using basic_set_t = std::unordered_set<T, hash>;

using value_t = boost::make_recursive_variant<
		int_t,
		basic_set_t<boost::recursive_variant_>
>::type;

using set_t = basic_set_t<value_t>;

struct hash
{
	// since boost 1.62 ... error: no match for call to ‘(const hash) (const boost::recursive_variant_&)’
	size_t operator()(const value_t& value) const
	{
		return 0;
	}
};

int main()
{
	set_t s;
	int_t i = 3;
	value_t v = i;
	s.emplace(v); // raises error above
	v = s;
	return 0;
}
}}}

gcc 6.2.0 on Linux[[BR]]
clang 7.0.2 on Mac"	Bugs	closed	Boost 1.64.0	variant	Boost 1.63.0	Regression	fixed