|  | 
        A type trait that determines whether a query expression is well-formed.
      
template<
    typename T,
    typename Property>
struct can_query
        Class template can_query is a trait that is derived from true_type
        if the expression asio::query(std::declval<T>(), std::declval<Property>())
        is well formed; otherwise false_type.
      
        Header: asio/query.hpp
      
        Convenience header: asio.hpp