////
Copyright 2005-2008 Daniel James
Copyright 2022 Christian Mazakas
Copyright 2022 Peter Dimov
Distributed under the Boost Software License, Version 1.0.
https://www.boost.org/LICENSE_1_0.txt
////

[#changes]
= Change Log
:idprefix: changes_

:int128: __int128

== Boost 1.67.0
* Moved library into its own module, `container_hash`.
* Moved headers for new module name, now at: `<boost/container_hash/hash.hpp>`, `<boost/container_hash/hash_fwd.hpp>`, `<boost/container_hash/extensions.hpp>`.
* Added forwarding headers to support the old headers locations.
* Support `std::string_view`, `std::error_code`, `std::error_condition`, `std::optional`, `std::variant`, `std::monostate` where available.
* Update include paths from other Boost libraries.
* Manually write out tuple overloads, rather than using the preprocessor to generate them. Should improve usability, due to better error messages, and easier debugging.
* Fix tutorial example (https://svn.boost.org/trac/boost/ticket/11017[#11017]).
* Quick fix for hashing `vector<bool>` when using libc++. Will try to introduce a more general fix in the next release.

== Boost 1.66.0
* Avoid float comparison warning when using Clang - this workaround was already in place for GCC, and was used when Clang pretends to be GCC, but the warning was appearing when running Clang in other contexts.

== Boost 1.65.0
* Support for `char16_t`, `char32_t`, `u16string`, `u32string`

[discrete]
== Boost 1.64.0
* Fix for recent versions of Visual {cpp} which have removed `std::unary_function` and `std::binary_function` (https://svn.boost.org/trac/boost/ticket/12353[#12353]).

[discrete]
== Boost 1.63.0
* Fixed some warnings.
* Only define hash for `std::wstring` when we know we have a `wchar_t`. Otherwise there's a compile error as there's no overload for hashing the characters in wide strings (https://svn.boost.org/trac/boost/ticket/8552[#8552]).

[discrete]
== Boost 1.58.0
* Fixed strict aliasing violation (https://github.com/boostorg/container_hash/issues/3[GitHub #3]).

[discrete]
== Boost 1.56.0
* Removed some Visual {cpp} 6 workarounds.
* Ongoing work on improving `hash_combine`. This changes the combine function which was previously defined in the reference documentation.

[discrete]
== Boost 1.55.0
* Simplify a SFINAE check so that it will hopefully work on Sun 5.9 (https://svn.boost.org/trac10/ticket/8822[#8822]).
* Suppress Visual {cpp} infinite loop warning (https://svn.boost.org/trac10/ticket/8568[#8568]).

[discrete]
== Boost 1.54.0
* https://svn.boost.org/trac/boost/ticket/7957[Ticket 7957]: Fixed a typo.

[discrete]
== Boost 1.53.0
* Add support for `boost::int128_type` and `boost::uint128_type` where available - currently only `{int128}` and `unsigned {int128}` on some versions of gcc.
* On platforms that are known to have the standard floating point functions, don't use automatic detection - which can break if there are ambiguous overloads.
* Fix undefined behaviour when using the binary `float` hash (Thomas Heller).

[discrete]
== Boost 1.52.0
* Restore `enum` support, which was accidentally removed in the last version.
* New floating point hasher - will hash the binary representation on more platforms, which should be faster.

[discrete]
== Boost 1.51.0
* Support the standard smart pointers.
* `hash_value` now implemented using SFINAE to avoid implicit casts to built in types when calling it.
* Updated to use the new config macros.

[discrete]
== Boost 1.50.0
* https://svn.boost.org/trac/boost/ticket/6771[Ticket 6771]: Avoid gcc's `-Wfloat-equal` warning.
* https://svn.boost.org/trac/boost/ticket/6806[Ticket 6806]: Support `std::array` and `std::tuple` when available.
* Add deprecation warning to the long deprecated `boost/container_hash/detail/container_fwd.hpp`.

[discrete]
== Boost 1.46.0
* Avoid warning due with gcc's `-Wconversion` flag.

[discrete]
== Boost 1.44.0
* Add option to prevent implicit conversions when calling `hash_value` by defining `BOOST_HASH_NO_IMPLICIT_CASTS`. When using `boost::hash` for a type that does not have `hash_value` declared but does have an implicit conversion to a type that does, it would use that implicit conversion to hash it. Which can sometimes go very wrong, e.g. using a conversion to `bool` and only hashing to 2 possible values. Since fixing this is a breaking change and was only approached quite late in the release cycle with little discussion it's opt-in for now. This, or something like it, will become the default in a future version.

[discrete]
== Boost 1.43.0
* https://svn.boost.org/trac/boost/ticket/3866[Ticket 3866]: Don't foward declare containers when using gcc's parallel library, allow user to stop forward declaration by defining the `BOOST_DETAIL_NO_CONTAINER_FWD` macro.
* https://svn.boost.org/trac/boost/ticket/4038[Ticket 4038]: Avoid hashing `0.5` and `0` to the same number.
* Stop using deprecated `BOOST_HAS_*` macros.

[discrete]
== Boost 1.42.0
* Reduce the number of warnings for Visual {cpp} warning level 4.
* Some code formatting changes to fit lines into 80 characters.
* Rename an internal namespace.

[discrete]
== Boost 1.40.0
* Automatically configure the `float` functions using template metaprogramming instead of trying to configure every possibility manually.
* Workaround for when STLport doesn't support long double.

[discrete]
== Boost 1.39.0
* Move the `hash_fwd.hpp` implementation into the hash subdirectory, leaving a forwarding header in the old location. You should still use the old location, the new location is mainly for implementation and possible modularization.
* https://svn.boost.org/trac/boost/ticket/2412[Ticket 2412]: Removed deprecated headers.
* https://svn.boost.org/trac/boost/ticket/2957[Ticket 2957]: Fix configuration for vxworks.

[discrete]
== Boost 1.38.0
* Changed the warnings in the deprecated headers from 1.34.0 to errors. These will be removed in a future version of Boost.
* Moved detail headers out of `boost/container_hash/detail`, since they are part of `functional/hash`, not `container_hash`. `boost/container_hash/detail/container_fwd.hpp` has been moved to `boost/detail/container_fwd.hpp` as it's used outside of this library, the others have been moved to `boost/functional/hash/detail`.

[discrete]
== Boost 1.37.0
* http://svn.boost.org/trac/boost/ticket/2264[Ticket 2264]: In Visual {cpp}, always use C99 float functions for long double and float as the {cpp} overloads aren't always availables.

[discrete]
== Boost 1.36.0
* Stop using OpenBSD's dodgy `std::numeric_limits`.
* Using the boost typedefs for `long long` and `unsigned long long`.
* Move the extensions into their own header.

[discrete]
== Boost 1.35.0
* Support for `long long`, `std::complex`.
* Improved algorithm for hashing floating point numbers:
** Improved portablity, as described by Daniel Krügler in http://lists.boost.org/boost-users/2005/08/13418.php[a post to the boost users list].
** Fits more information into each combine loop, which can reduce the the number of times combine is called and hopefully give a better quality hash function.
** Improved the algorithm for hashing floating point numbers.
** On Cygwin use a binary hash function for floating point numbers, as Cygwin doesn't have decent floating point functions for `long double`.
** Never uses `fpclass` which doesn't support `long double`.
** http://svn.boost.org/trac/boost/ticket/1064[Ticket 1064]: Removed unnecessary use of errno.
* Explicitly overload for more built in types.
* Minor improvements to the documentation.
* A few bug and warning fixes:
** http://svn.boost.org/trac/boost/ticket/1509[Ticket 1509]: Suppress another Visual {cpp} warning.
** Some workarounds for the Sun compilers.

[discrete]
== Boost 1.34.1
* https://svn.boost.org/trac10/ticket/952[Ticket 952]: Suppress incorrect 64-bit warning on Visual {cpp}.

[discrete]
== Boost 1.34.0
* Use declarations for standard classes, so that the library doesn't need to include all of their headers
* Deprecated the `<boost/functional/hash/*.hpp>` headers. Now a single header, `<boost/functional/hash.hpp>` is used.
* Add support for the `BOOST_HASH_NO_EXTENSIONS` macro, which disables the extensions to TR1.
* Minor improvements to the hash functions for floating point numbers.
* Update the portable example to hopefully be more generally portable.

[discrete]
== Boost 1.33.1
* Fixed the points example, as pointed out by 沈慧峰.

[discrete]
== Boost 1.33.0
* Initial Release
