id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
12285	type_traits must assert type completeness for some traits	Antony Polukhin	John Maddock	"Without that check hard detectable errors are possible:

{{{
#include <boost/type_traits.hpp>

struct foo;

void kill_sanity() {
    (void)boost::is_constructible<foo, foo>::value;
}

struct foo{};

int main() {
    static_assert(boost::is_constructible<foo, foo>::value, ""foo must be constructible from foo""); // Ooops
}
}}}

All the is_*constructible, is_base_of, is_convertible, is_destructible, is_*swappable, has_virtual_destructor traits must assert completeness.

Solution could be to create an asserting structure (pseudocode):

{{{
template <class T>
struct assert_complete {
    template <class U> yes_type test(mpl::int_<sizeof(U)>* = 0);
    template <class U> no_type test(...);

    static_assert(sizeof(test<T>(0)) == sizeof(yes_type), ""T must be a complete type!"");
};
}}}"	Bugs	closed	To Be Determined	type_traits	Boost 1.61.0	Problem	fixed