Boost.Function now implements allocator support
in the same way that is is provided in C++0x, based on C++
proposal N2308. This
change removes the
template parameter of
favor of a constructor that takes an argument. While this is a
backward-incompatible change, it is likely to affect only a few
users. This change to Function was contributed by Emil
Dotchevski, which also authored the corresponding C++ committee
Boost.Function now implements a small buffer optimization, which can drastically improve the performance when copying or construction Boost.Function objects storing small function objects. For instance,
bind(&X:foo, &x, _1, _2) requires no heap allocation when placed into a Boost.Function object. Note that some exception-safety guarantees have changed: assignment provides the basic exception guarantee and
swap() may throw.
All features deprecated in version 1.29.0 have been removed from Boost.Function.
boost::bad_function_call exception class
Version 1.29.0: Boost.Function has been partially redesigned to minimize the interface and make it cleaner. Several seldom- or never-used features of the older Boost.Function have been deprecated and will be removed in the near future. Here is a list of features that have been deprecated, the likely impact of the deprecations, and how to adjust your code:
boost::function class template syntax has
changed. The old syntax, e.g.,
double, std::string>, has been changed to a more natural
boost::function<int (float, double,
std::string)>, where all return and argument types are
encoded in a single function type parameter. Any other template
parameters (e.g., the
Allocator) follow this single
The resolution to this change depends on the
abilities of your compiler: if your compiler supports template
partial specialization and can parse function types (most do), modify
your code to use the newer
syntax (preferable) or directly use one of the
functionN classes whose syntax has not
changed. If your compiler does not support template partial
specialization or function types, you must take the latter option and
use the numbered Boost.Function classes. This option merely requires
changing types such as
boost::function<void, int, int>
boost::function2<void, int, int> (adding the number of
function arguments to the end of the class name).
Support for the old syntax with the
boost::function class template will persist for a short
while, but will eventually be removed so that we can provide better
error messages and link compatibility.
policy template parameter (
Policy) has been deprecated
and will be removed. There is no direct equivalent to this rarely
The mixin template parameter
Mixin) has been deprecated and will be removed. There
is not direct equivalent to this rarely used feature.
set methods have been deprecated and will be
removed. Use the assignment operator instead.
Last revised: July 14, 2008 at 14:32:29 -0400