...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Determine the amount of data that may be read without blocking.
std::size_t in_avail( boost::system::error_code & ec);
This function is used to determine the amount of data, in bytes, that may be read from the stream without blocking.
Set to indicate what error occurred, if any.
The number of bytes of data that can be read without blocking.