#include <istream>
#include <type_traits>
int main()
{
static_assert((std::is_base_of<std::basic_istream<char>, std::basic_iostream<char> >::value), "");
static_assert((std::is_base_of<std::basic_ostream<char>, std::basic_iostream<char> >::value), "");
static_assert((std::is_same<std::basic_iostream<char>::char_type, char>::value), "");
static_assert((std::is_same<std::basic_iostream<char>::traits_type, std::char_traits<char> >::value), "");
static_assert((std::is_same<std::basic_iostream<char>::int_type, std::char_traits<char>::int_type>::value), "");
static_assert((std::is_same<std::basic_iostream<char>::pos_type, std::char_traits<char>::pos_type>::value), "");
static_assert((std::is_same<std::basic_iostream<char>::off_type, std::char_traits<char>::off_type>::value), "");
}