The library is now compatible with Boost 1.53 or newer. Boost.Filesystem
v2 no longer supported.
The library now does not introduce separate logging cores for different
character types. A lot of other library components also became character
type agnostic. The application can now use loggers of different character
types with the common logging core. The library performs character code
conversion as needed. Boost.Locale
can be used to construct locale objects for proper encoding conversion.
configuration macro has been replaced with
with the opposite meaning. The support for compiler intrinsics for TLS
is now disabled by default.
Added configuration macros
macro renamed to
The new macros allow to selectively disable support for the corresponding
The library now uses Boost.Xpressive
instead of Boost.Regex
internally which makes it unnecessary to build the latter in order to use
the library. Boost.Regex
is still supported on the user's side.
Made some internal code to detect Windows NT6 API availability at run time,
if not explicitly enabled by the
macro. The code compiled without the macro defined will still be able run
on NT5, but when run on NT6 it will be more efficient. With the macro defined
the resulting code will not run on NT5, but will be a little more efficient
on NT6 than without the macro.
Added a concept of a default sink. The default sink is used when there
are no sinks configured in the logging core. The sink is synchronous and
thread-safe, it requires no configuration and is overridden by any sinks
configured in the core by user. The default sink will write log messages
to the console, prepending with a timestamp, thread id and severity level.
Trivial logging no longer implicitly initializes the library. Instead,
the default sink is used to display log messages, unless the library is
configured otherwise. It is now possible to use both trivial and advanced
Attribute values can now be added to log records after filtering. Such
values do not participate in filtering but can be used by formatters and
sinks. Log record message is now one of such attribute values, it is no
longer directly accessible from the log record interface.
Formatters and sinks no longer operate on log records but rather on
record_views. Records are now
moved from when pushed to the core for further processing. This is done
in order to eliminate the possibility of unsafe record modification after
pushing to the core. As a consequence, log records can no longer be copied,
only moving is allowed. Record views can be copied and moved; copying is
a shallow operation.
The implementation now provides several stream manipulators. Notably, the
to_log manipulator allows to customize
formatting for particular types and attributes without changing the regular
streaming operator. Also, the
add_value manipulator can be used
in logging expressions to attach attribute values to the record.
Made a lot of improvements to speedup code compilation.
Changed the interface and the way of handling attribute values. The value
is now a pimpl wrapper around the value holder. The
class in various components of the library is no longer pointed to with
shared_ptrs but instead
is handled by value. This allowed to simplify attribute value handling
in simple cases.
Similarly to attribute values, the interface of attributes has been reworked
in the pimpl fashion. All attributes now derive from the
base class, which holds the reference to the implementation. All attributes
now have to be created by value rather than wrapped into
shared_ptr by user, which makes the code
Added support for casting attributes from the base class
to the actual attribute type. This can be useful when the concrete attribute
factory provides additional interfaces.
The attribute value no longer has the
method. Use the
function as a replacement.
The key type of attribute sets and attribute values set has been changed.
The new key type is called
It is constructible from strings, so in most cases users won't need to
change the code. See here
for more information.
Attribute values view have been renamed to attribute value set. The container
now supports adding more attribute values after being constructed.
Attribute sets and attribute value sets no longer maintain order of elements.
Although it wasn't stated explicitly, the containers used to be ordered
associative containers. Now the order of elements is unspecified. The implementation
has been reworked to speed up insertion/removal of attributes, as well
as attribute lookup and values set construction. The drawback is that memory
footprint may get increased in some cases.
Attribute sets now use small memory pools to speed up element insertion/removal.
utility to the
attributes directory. The
utility has been replaced
The two new headers define the revised API of attribute value extraction
and visitation, respectively. See here
for more details.
attibute macros simplified. The attribute constructor arguments
are specified next to the attribute type and tag type is no longer required.
attribute no longer uses
type for thread identification. An internal type is used instead, the type
is accessible as
The new thread ids are taken from the underlying OS API and thus more closely
correlate to what may be displayed by debuggers and system diagnostic tools.
The attribute generates a string with the executable name of the current
functor attribute has
been renamed to
The generator function has been renamed from
make_function. The header
has been renamed from
Fixed compilation problems with exception handling logger feature.
Global logger storage made more friendly to the setups in which hidden
visibility is set by default.
Added the macros for separated global logger declaration and definition.
Old macros have been renamed to better reflect their effect (
Also, the macros no longer define the
free function for logger acquisition. Use
instead. See here
for more information.
The channel logger now supports changing the channel name after construction.
The channel name can be set either by calling the modifier method or by
specifying the name in the logging statement. Added
(as well as their shorthands
macros that allow to specify channel name for the log record.
Types for integral constants for syslog and event log were renamed to drop
Formatting functionality moved to sink frontends. Sink backends that support
record formatting derive from the
class template, which indicates to the frontend that record formatting
is required. This breaks user-side API of the library: the formatter and
locale has to be set to the frontend rather than backend.
Formatting support no longer makes frontend thread synchronization mandatory.
Formatting is done prior to locking for processing the record in the backend
and can be performed concurrently in multiple threads.
Added support for flushing sinks. A sink backend that supports flushing
has to define public method with the following signature:
Asynchronous sink frontend reworkerd, ordering asynchronous sink removed.
class template now allows to specify record queueing strategy. Several
strategies provided, including
(the default) and
which cover the functionality of asynchronous sink frontends in 1.x releases.
See the asynchronous
sink frontend docs for more details.
Lock-free FIFO record queueing in asynchronous sinks reworked to reduce
log record processing stalls.
file parameter for text file sinks. If this parameter is set to
true, the sink will append log records to
the existing log file instead of overwriting it.
Added bounded variants of asynchronous sink frontends. Implemented two
strategies to handle queue overflows: either log records are dropped or
logging threads are blocked until there is space in the queue.
Filters and formatters:
As a result of character type unification, filters no longer depend on
the character type.
Two new types were introduced to dynamically store filters and formatters:
Both new types implement type erasure and provide function calling operators
to invoke the stored filter or formatter.
Filters and formatters were rewritten. The new implementation is based
and resides in the
namespace. Attribute placeholders are now interoperable with other template
expressions based on Boost.Phoenix.
All template expression headers now reside in the
The library now supports defining keywords for attributes (see
BOOST_LOG_ATTRIBUTE_KEYWORD macro). Keywords
can be used in template expressions instead of attribute placeholders and
also as a key in container lookups.
Filters and formatters do not throw exceptions by default when an attribute
value cannot be used to complete the function (e.g. when the value is missing
or has inappropriate type). The offending filter subexpression will return
false in such cases, the formatter
will result in empty string instead of the value. The behavior can be changed
or_throw member functions
on the attribute value placeholder in the filtering/formatting expression.
Date and time formatter implementation is not based on Boost.DateTime
IO facets anymore. The new implementation improves formatting performance.
The formatter has been renamed to
Named scope formatter now supports scope format specification. The scope
format can include the scope name, as well as file name and line number.
The formatter has been renamed to
decorators were renamed to
The generic character decorator is named
Added a new channel
severity filter. The filter allows to setup severity thresholds
for different channels. The filter checks log record severity level against
the threshold corresponding to the channel the record belongs to.
Most code examples from the docs have been extracted into compilable standalone
examples, which can be used for testing and experimenting with the library.
Added a lot of cross-references to the documentation, which should simplify
Fixed a bug: the logging core could enter an infinite loop inside
push_record if a sink throws and the
exception is suppressed by the exception handler set in the core.
Changed the type dispatching implementation to reduce the usage of virtual
functions. This greatly reduced the library size.
Type dispatchers made more friendly to the setups in which hidden visibility
is set by default.
The interface of type dispatchers changed. The dispatcher now returns
type_visitor instance by
value, and the visitor is no longer a base for the actual receiver of the
dispatched value. Instead, the visitor now refers to the receiver, if one
is capable to consume the value. The
method has been renamed to
(). The static type dispatcher now
requires a reference to the receiver on construction, it doesn't imply
that the receiver derives from the dispatcher anymore.
has been removed. There is no replacement.
The library now uses many features from the latest C++ standard (aka C++11).
For instance, many library components now support move semantics. Boost.Move
is used for move emulation on C++03-compatible compilers.
This release mostly fixes bugs in the code and documentation.
Added support for Boost.Filesystem
A number of bugs fixed.
Corrections in the documentation.
This release mostly fixes bugs in the code and documentation. The next major
release (2.0) will contain breaking changes and feature additions. The 1.0
branch will not receive any feature updates.
Added some optimization for thread local storage. In Windows setups, if
you dynamically load Boost.Log binaries during the application run time,
this optimization may lead to crashes. In that case, you may disable it
during the library build process. The macro also affects other platforms,
which may be useful if your compiler does not support TLS.
Added a few public accessors and convenience constructors to severity and
Added ability to rotate log files at the specified time points. The
rotation_interval keyword is no longer
available. The same functionality is achieved with the new
time_based_rotation keyword and the
predicate. See here
for more details.
Improved support for MinGW and Cygwin.
A number of bugs fixed. Added workarounds to compile on GCC 4.2.
Lots of corrections in the documentation.
Substantial documentation improvement. The tutorial section has been reorganized.
Library headers have been reorganized. Some other Boost libraries that
were previously included by headers have been made optional. Such dependencies
have been extracted into separate headers in the
directory. Top level library headers now mostly include nested headers.
Keywords have moved into a dedicated
namespace. There are no longer nested
attributes, etc. All keywords have been
extracted into separate headers in the
Removed rotating file stream. As a replacement, a new
file sink has been added, which allows to achieve the same results
ans adds a few more features.
Added a new multifile
Added a new ordering asynchronous sink frontend.
The syslog sink
backend is now supported on Windows, too. The sink no longer requires native
support for POSIX API for syslog, but is able to send syslog packets to
a remote server over UDP.
Loggers implementation has been improved. Feature composition mechanism
has been cleaned up.
Added support for scoped logging. There is now a distinct log
record entity, which is returned by the core as a result of filtering.
It is possible to fill in the record message in any way the user wants,
not necessarilly with a streaming expression. The record object is now
processed by sinks and formatters.
Added support for exception control. User can register exception handlers
at one of the three layers: for a particular sink, at the core layer, and
for a particular logger (given that it has the appropriate feature). Sinks
and core will not suppress exceptions by default. Filter and formatters
will throw if the requested attribute value is not found.
Added a few new formatters, called character decorators. These can be useful
to post-process the formatted output before passing it on to the sink.
Added attributes for thread and process identifiers. These identifiers
are automatically added after the call to
Helper initialization functions, such as
now accept more customization options as named arguments.
A new initialization
interface has been exposed. One can fill a settings container and
use it to initialize the library.
The library setup support code has beed extracted into a separate binary.
Further on, this binary will be made optional to build.
Added a new mode of logging, called trivial logging. In this mode the library
requires no initialization at all, however it does not offer many ways
A number of bugs fixed.
A few optimizations added to improve multithreaded applications performance.
Removed some bug workarounds for older Boost releases. The library now
requires Boost 1.39 or newer.
Substantial documentation improvement.
Added several Windows-specific sinks: Event Log (simplified and advanced),
Windows debugger and experimental Event Trace for Windows Vista and later.
Loggers now consist of a number of independent features that can be composed
the way the user needs. User-defined features can be developed and injected
into the mix.
Attribute value extractors improved. With the new extract function attribute
values can be extracted from the attribute values view by employing lambda
Some files and classes were moved or renamed to improve code clarity and
A number of bugs fixed.
Noone really remembers these dark ages...