The boost::asio::buffer_size function determines the total number of bytes in a buffer or buffer sequence.

std::size_t buffer_size(
    const mutable_buffer & b);
  » more...

std::size_t buffer_size(
    const mutable_buffers_1 & b);
  » more...

std::size_t buffer_size(
    const const_buffer & b);
  » more...

std::size_t buffer_size(
    const const_buffers_1 & b);
  » more...

template<
    typename BufferSequence>
std::size_t buffer_size(
    const BufferSequence & b);
  » more...

Requirements

Header: boost/asio/buffer.hpp

Convenience header: boost/asio.hpp