Function compare_predicate

test/value_test.cpp:568–573

template <class Expression>
static auto compare_predicate(const Expression& e)
{
    bool result = e.value();
    return test::make_predicate(test::as_string(e) + " => " + test::as_string(result),
                                [=] { return result; });
}

TEST_CASE(value_compare)
{