Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
This is an older version of Boost and was released in 2018. The current version is 1.91.0.
This version fixes a missing executor work guard in all composed operations used in the implementation. Users who are experiencing crashes related to asynchronous completion handlers are encouraged to upgrade. Also included is an improved mechanism for generating random numbers used to mask outgoing websocket frames when operating in the client mode. This resolves a vulnerability described in the Beast Hybrid Assessment Report from Bishop Fox.
New Features
The include directory <beast/experimental> contains features which are not part of
the stable public interface but are available anyway. They may change in future
versions.
flat_stream for working around
an SSL stream performance limitation
http::icy_stream stream filter allows
parsing ICY HTTP response handshakes
ssl_stream
for better SSL performance and move constructability
test::connect,
test::error,
test::fail_count,
and test::stream
utilities for writing unit tests.
http::is_mutable_body_writer metafunction
websocket::seed_prng for manually providing
entropy to the PRNG
websocket::stream::secure_prng to control whether
the connection uses a secure PRNG
Improvements
buffers_adapter
handler_ptr::has_value
Fixes
const and
non-const overloads for message
based HTTP writes
bind_handler
http::parser constructor javadoc
buffers_adapter iterator value
type
buffers_adapter::max_size
buffers_prefix iterator decrement
Breaking Changes
serializer::reader_impl
reader and writer ctor signatures
This version fixes significant defects in websocket::stream which can lead to asserts or
undefined behavior. Users are encouraged to update to the latest Boost release.
New Features
bool
template parameter to websocket::stream When deflateSupported
is true, the stream will be
capable of negotiating the permessage-deflate websocket extension per the
configured run-time settings. When deflateSupported
is false, the stream will
never negotiate the permessage-deflate websocket extension. Furthermore,
all of the code necessary for implementing the permessage-deflate extension
will be excluded from function instantiations. Programs which set deflateSupported to false
when instantiating streams will be smaller.
websocket::error::failed and websocket::error::handshake_failed
are removed. Actions required: Code which explicitly compares error_code values against the constant
websocket::error::handshake_failed should compare against
websocket::condition::handshake_failed instead. Code
which explicitly compares error_code values against the constant websocket::error::failed should compare against websocket::condition::protocol_violation instead.
Improvements
http::basic_fields uses less storage
http::basic_fields exception specifiers
are provided
asio::null_buffers
<boost/beast/websocket/stream_fwd.hpp>
bind_handler
works with boost placeholders
reuse_address(true)
Fixes
ssl_stream
special members in example/common/ssl_stream.hpp
<algorithm> are protected from macros
http::basic_fields::erase
bind_handler doc
"ws_.wr_block_ == tok_".
API Changes
handler_ptr. Actions required:
don't call non-public members.
handler_ptr
is a move-only type, with unique_ptr
semantics. Actions required: user-defined composed operations using handler_ptr to manage state can only
be moved, not copied.
handler_ptr
gives the strong exception guarantee. The constructor signature for managed
objects constructed by handler_ptr
now receives a const reference
to the handler. Actions required: Change the constructor signature for
state objects used with handler_ptr
to receive a const reference
to the handler.
http::basic_fields does not support
fancy pointers
http::parser
is no longer MoveConstructible
http::serializer::reader_impl is deprecated and will be
removed in the next release. Actions required: Call http::serializer::writer_impl instead of serializer::reader_impl.
http::header and value_type
objects. This enables the composition of body types. The previous single-argument
constructors are deprecated and will be removed in the next version. Actions
required: Change user-defined instances of BodyReader or BodyWriter constructor signatures to the
two-argument form. Alternatively. define the macro BOOST_BEAST_ALLOW_DEPRECATED
in the project (which will cause both the new and the deprecated signatures
to be accepted).
websocket::stream::control_callback now copies or
moves the function object.
get_lowest_layer
is now a type alias. Actions required: Replace instances of typename get_lowest_layer<T>::type
with get_lowest_layer<T>.