|  | 
        The is_async_operation
        trait detects whether a type T
        and arguments Args... may
        be used to initiate an asynchronous operation.
      
template< typename T, typename... Args> struct is_async_operation : public integral_constant< bool, automatically_determined >
        Class template is_async_operation
        is a trait is derived from true_type
        if the expression T(Args..., token)
        initiates an asynchronous operation, where token
        is an unspecified completion token type. Otherwise, is_async_operation
        is derived from false_type.
      
        Header: asio/async_result.hpp
      
        Convenience header: asio.hpp