fix#1417
* New get_lowest_layer free function works for any object
* New lowest_layer_type trait works for any object
* New examples and documentation on layered streams
API Changes:
* The member function lowest_layer is removed from all
types provided by the library:
Actions Required:
* Call the free function get_lowest_layer instead of
member lowest_layer.
* The function buffers is deprecated, use the new
function make_printable as the replacement.
Actions Required:
* Replace call sites to use make_printable instead of buffers,
and also include make_printable.hpp instead of ostream.hpp.
fix#1290
* BOOST_ASIO_NO_DEPRECATED=1 is now set
* Fix various warnings from the Boost regression test matrix
* Fix a bug in advanced servers when checking for a timeout
fix#1237
HTTP client examples now verify the server's certificate
and generate an error if the certificate is invalid or
expired:
* Set certificate verify mode
* Remove duplicate root certificate
The ssl_stream wrapper provides C++11 move semantics for ssl::stream,
as well as incorporating the flat_stream workaround for a performance
problem with ssl::stream writes and buffer sequences having length
greater than one.
fix#1108
The `flat_stream` is a stream wrapper designed to overcome a
performance limitation of the `boost::asio::ssl::stream`
implementation. Specifically, when writing buffer sequences having
length greater than one, the `ssl::stream` implementation does
not use scatter-gather I/O and instead performs a kernel transition
for every buffer in the sequence.
The wrapper addresses this problem by allocating memory and
presenting the buffer sequence into a single buffer, using
some logic to determine when this allocation is advantageous
versus simply passing the buffers through as-is.
See Also:
https://github.com/boostorg/asio/issues/100https://stackoverflow.com/questions/50026167/performance-drop-on-port-from-beast-1-0-0-b66-to-boost-1-67-0-beast
fix#1076
As per Asio and Networking TS requirements, composed operations must
maintain an object of type executor_work_guard for the executor associated
with the I/O object, for the lifetime of the asynchronous operation.
This is in addition to the requirement for maintaining an object of type
executor_work_guard for the executor associated with the handler.
