Those are old compilers and removing support allows removing a couple
of workarounds. It also reduces the CI burden and will allow us to test
more recent and more relevant compilers.
Here is the test result:
100% tests passed, 0 tests failed out of 1103
Here are the details of the source workarounds:
1. Active issues we are working on
a. Multiple copy/move ctors
VC doesn't correctly handle multiple copy/move ctors.
The workaround is under macro BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654.
b. Forward declaration of class template member function returning decltype(auto) (this issue is exposed by a recent change in boost 1.68)
To deduce the actual return type, the compiler expects the function definition to be on the pending list for temploid, which isn't always the case when generic lambda is involved.
The workaround is under macro BOOST_HANA_WORKAROUND_MSVC_DECLTYPEAUTO_RETURNTYPE_662735
2. Issues fixed in the development branch of MSVC
Parsing template id
VC sometimes incorrectly parses a comparison operation as a template id.
The workaround is under macro BOOST_HANA_WORKAROUND_MSVC_RDPARSER_TEMPLATEID_616568.
3. Issues fixed conditionally
a. Empty base optimization
VC doesn't always do EBO (empty base optimization). Changing this will break the ABI of MSVC and we provide a __declspec(empty_bases) to enable EBO.
We have a blog post on this: https://blogs.msdn.microsoft.com/vcblog/2016/03/30/optimizing-the-layout-of-empty-base-classes-in-vs2015-update-2-3/.
Some tests in hana have static_assert on the size of certain types which relies on EBO being applied:
hana\test\detail\ebo.cpp
hana\test\issues\github_202.cpp
hana\test\pair\empty_storage.cpp
hana\test\tuple\empty_member.cpp
The workaround is under macro BOOST_HANA_WORKAROUND_MSVC_EMPTYBASE.
b. Variadic macro expansion
The implementation of variadic macro isn't conformant and the macro expansion often results in incorrect result.
The issue is fixed under /experimental:preprocessor and isn't on by default yet.
We have a blog post on this: https://blogs.msdn.microsoft.com/vcblog/2018/07/06/msvc-preprocessor-progress-towards-conformance/.
The workaround is under macro BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033.
Here is the list of files impacted by the source workarounds:
BOOST_HANA_WORKAROUND_MSVC_MULTIPLECTOR_106654
hana\test\_include\laws\base.hpp
hana\test\map\cnstr.trap.cpp
hana\test\set\cnstr.trap.cpp
hana\test\tuple\cnstr.trap.cpp
BOOST_HANA_WORKAROUND_MSVC_DECLTYPEAUTO_RETURNTYPE_662735
hana\test\_include\laws\euclidean_ring.hpp
hana\test\_include\laws\group.hpp
hana\test\_include\laws\monad_plus.hpp
hana\test\_include\laws\monoid.hpp
hana\test\_include\laws\ring.hpp
BOOST_HANA_WORKAROUND_MSVC_RDPARSER_TEMPLATEID_616568
hana\include\boost\hana\basic_tuple.hpp
hana\include\boost\hana\string.hpp
hana\include\boost\hana\tuple.hpp
BOOST_HANA_WORKAROUND_MSVC_EMPTYBASE
hana\include\boost\hana\basic_tuple.hpp
hana\include\boost\hana\pair.hpp
hana\include\boost\hana\tuple.hpp
hana\include\boost\hana\detail\integral_constant.hpp
hana\test\detail\ebo.cpp
BOOST_HANA_WORKAROUND_MSVC_PREPROCESSOR_616033
hana\include\boost\hana\detail\preprocessor.hpp
hana\include\boost\hana\detail\struct_macros.hpp
BTW,
1. There are some warnings which I don't fix. I will likely address them in a separate PR. They look legit and don't impact the build and tests.
2. Appveyor currently doesn't provide 15.8 Preview 5 which contains all the compiler fixes we made in the previous months. I plan to update appveyor.yml after Appveyor provides 15.8 RTM.
Also, add tests to make sure that an empty pair can be EBO'd. This one is very
important because a typical use case is to create a tuple of pairs of empty
types (e.g. in hana::map), and we expect this to be empty.
This is done by generating the supporting preprocessor macros with ERB up to
the required arity, like we do for the struct macros themselves.
Fixes#376
This used to guard against a bug in the std::tuple implementation, but it
seems like this bug was fixed in subsequent minor releases of Clang 3.5 and
3.6, which we test against.
Those tests were broken with older versions of Boost that we don't test
against anymore. Furthermore, since we document that Boost and standalone
Hana installations should not be mixed, there's no risk of this change
breaking any existing code (that would be mixing standalone Hana with an
old version of Boost).
The idea was given to me by Daniel Pfeifer (@purpleKarrot), who said it may
actually help find ODR issues better. In any case, this simplifies the script
and reduces the (otherwise overwhelming) number of targets.
- Adds index_if
- Rewrites detail::index_if to use recursive alias stuff
optimized for tuple and basic_tuple
- find_if now uses index_if for Iterables
- at_key now uses index_if for Sequence
- Removes duplicate code and unnecessary special case implementations
- detail::advance_until
- at_key::advance_until
- tuple_tag implementation of find_if
- Uses Foldable instead of Sequence for cases where length is known.
(find_if had a specialization when Iterable and not Sequence)
- Adds test.*.auto.index_if for Sequences
- Adds test support/counter for testing infinite iterables
This commit decouples the underlying representation of basic_tuple from many
utilities and containers in Hana. This will lead to better support for EBO and
cleaner code, however it might result in a slight compile-time pessimization
since there's one more function instantiation than using `get_impl` directly,
and we're adding 3 overloads to `at_c`.
Also, add automatic unit tests for any_of, all_of and none_of. This commit
also makes it easier to add new automatic unit tests by documenting a small
shell script.
Commit triggered by http://stackoverflow.com/q/42012512/627587
