Query the current value of the blocking property.

static constexpr execution::blocking_t query(
    execution::blocking_t );

Do not call this function directly. It is intended for use with the query customisation point.

For example:

boost::asio::inline_or_executor<my_executor_type> ex = ...;
if (boost::asio::query(ex, boost::asio::execution::blocking)
    == boost::asio::execution::blocking.possibly)
  ...