Change Log

Review Version

Initial review version, for the review conducted from 7th December 2007 to 16th December 2007.

1.35.0 Add-on - 31st March 2008

Unofficial release uploaded to vault, to be used with Boost 1.35.0. Incorporated many of the suggestions from the review.

Improved portability thanks to Boost regression testing.
Fix lots of typos, and clearer text in the documentation.
Fix floating point to std::size_t conversion when calculating sizes from the max load factor, and use double in the calculation for greater accuracy.
Fix some errors in the examples.

Boost 1.36.0

First official release.

Rearrange the internals.
Move semantics - full support when rvalue references are available, emulated using a cut down version of the Adobe move library when they are not.
Emplace support when rvalue references and variadic template are available.
More efficient node allocation when rvalue references and variadic template are available.
Added equality operators.

Boost 1.37.0

Rename overload of emplace with hint, to emplace_hint as specified in n2691.
Provide forwarding headers at <boost/unordered/unordered_map_fwd.hpp> and <boost/unordered/unordered_set_fwd.hpp>.
Move all the implementation inside boost/unordered, to assist modularization and hopefully make it easier to track changes in subversion.

Boost 1.38.0

Use boost::swap.
Ticket 2237: Document that the equality and inequality operators are undefined for two objects if their equality predicates aren't equivalent. Thanks to Daniel Krügler.
Ticket 1710: Use a larger prime number list. Thanks to Thorsten Ottosen and Hervé Brönnimann.
Use aligned storage to store the types. This changes the way the allocator is used to construct nodes. It used to construct the node with two calls to the allocator's construct method - once for the pointers and once for the value. It now constructs the node with a single call to construct and then constructs the value using in place construction.
Add support for C++0x initializer lists where they're available (currently only g++ 4.4 in C++0x mode).

Boost 1.39.0

Ticket 2756: Avoid a warning on Visual C++ 2009.
Some other minor internal changes to the implementation, tests and documentation.
Avoid an unnecessary copy in operator[].
Ticket 2975: Fix length of prime number list.

Boost 1.40.0

Ticket 2975: Store the prime list as a preprocessor sequence - so that it will always get the length right if it changes again in the future.
Ticket 1978: Implement emplace for all compilers.
Ticket 2908, Ticket 3096: Some workarounds for old versions of borland, including adding explicit destructors to all containers.
Ticket 3082: Disable incorrect Visual C++ warnings.
Better configuration for C++0x features when the headers aren't available.
Create less buckets by default.

Boost 1.41.0 - Major update

The original version made heavy use of macros to sidestep some of the older compilers' poor template support. But since I no longer support those compilers and the macro use was starting to become a maintenance burden it has been rewritten to use templates instead of macros for the implementation classes.
The container objcet is now smaller thanks to using boost::compressed_pair for EBO and a slightly different function buffer - now using a bool instead of a member pointer.
Buckets are allocated lazily which means that constructing an empty container will not allocate any memory.

Boost 1.42.0

Support instantiating the containers with incomplete value types.
Reduced the number of warnings (mostly in tests).
Improved codegear compatibility.
Ticket 3693: Add erase_return_void as a temporary workaround for the current erase which can be inefficient because it has to find the next element to return an iterator.
Add templated find overload for compatible keys.
Ticket 3773: Add missing std qualifier to ptrdiff_t.
Some code formatting changes to fit almost all lines into 80 characters.

Boost 1.43.0

Ticket 3966: erase_return_void is now quick_erase, which is the current forerunner for resolving the slow erase by iterator, although there's a strong possibility that this may change in the future. The old method name remains for backwards compatibility but is considered deprecated and will be removed in a future release.
Use Boost.Exception.
Stop using deprecated BOOST_HAS_* macros.

Boost 1.45.0

Fix a bug when inserting into an unordered_map or unordered_set using iterators which returns value_type by copy.

Boost 1.48.0 - Major update

This is major change which has been converted to use Boost.Move's move emulation, and be more compliant with the C++11 standard. See the compliance section for details.

The container now meets C++11's complexity requirements, but to do so uses a little more memory. This means that quick_erase and erase_return_void are no longer required, they'll be removed in a future version.

C++11 support has resulted in some breaking changes:

Equality comparison has been changed to the C++11 specification. In a container with equivalent keys, elements in a group with equal keys used to have to be in the same order to be considered equal, now they can be a permutation of each other. To use the old behavior define the macro BOOST_UNORDERED_DEPRECATED_EQUALITY.
The behaviour of swap is different when the two containers to be swapped has unequal allocators. It used to allocate new nodes using the appropriate allocators, it now swaps the allocators if the allocator has a member structure propagate_on_container_swap, such that propagate_on_container_swap::value is true.
Allocator's construct and destroy functions are called with raw pointers, rather than the allocator's pointer type.
emplace used to emulate the variadic pair constructors that appeared in early C++0x drafts. Since they were removed it no longer does so. It does emulate the new piecewise_construct pair constructors - only you need to use boost::piecewise_construct. To use the old emulation of the variadic consturctors define BOOST_UNORDERED_DEPRECATED_PAIR_CONSTRUCT.

Boost 1.49.0

Fix warning due to accidental odd assignment.
Slightly better error messages.

Boost 1.50.0

Fix equality for unordered_multiset and unordered_multimap.
Ticket 6857: Implement reserve.
Ticket 6771: Avoid gcc's -Wfloat-equal warning.
Ticket 6784: Fix some Sun specific code.
Ticket 6190: Avoid gcc's -Wshadow warning.
Ticket 6905: Make namespaces in macros compatible with bcp custom namespaces. Fixed by Luke Elliott.
Remove some of the smaller prime number of buckets, as they may make collisions quite probable (e.g. multiples of 5 are very common because we used base 10).
On old versions of Visual C++, use the container library's implementation of allocator_traits, as it's more likely to work.
On machines with 64 bit std::size_t, use power of 2 buckets, with Thomas Wang's hash function to pick which one to use. As modulus is very slow for 64 bit values.
Some internal changes.