This recommits r290512 that was reverted when MSVC failed to compile it. Since
then I've played with various approaches using rextester.com (where I was able
to reproduce the failure) and think that I have a solution thanks in part to
the help of Dave Blaikie! It seems MSVC just has a defective `decltype` in this
version. Manually writing out the type seems to do the trick, even though it is
.... quite complicated.
Original commit message:
This allows both defining convenience iterator/range accessors on types
which walk across N different independent ranges within the object, and
more direct and simple usages with range based for loops such as shown
in the unittest. The same facilities are used for both. They end up
quite small and simple as it happens.
I've also switched an iterator on `Module` to use this. I would like to
add another convenience iterator that includes even more sequences as
part of it and seeing this one already present motivated me to actually
abstract it away and introduce a general utility.
Differential Revision: https://reviews.llvm.org/D28093
llvm-svn: 290528
This code doesn't work on MSVC for reasons that elude me and I've not
yet covinced a workaround to compile cleanly so reverting for now while
I play with it.
llvm-svn: 290513
This allows both defining convenience iterator/range accessors on types
which walk across N different independent ranges within the object, and
more direct and simple usages with range based for loops such as shown
in the unittest. The same facilities are used for both. They end up
quite small and simple as it happens.
I've also switched an iterator on `Module` to use this. I would like to
add another convenience iterator that includes even more sequences as
part of it and seeing this one already present motivated me to actually
abstract it away and introduce a general utility.
Differential Revision: https://reviews.llvm.org/D28093
llvm-svn: 290512
llvm::cl already has a function called llvm::apply() so this is
causing an ODR violation. The STLExtras version should win the
vote on which one gets to be called apply() since it is named
after the equivalent STL function, but since renaiming the cl
version is more difficult, let's do this for now to get the
bots green.
llvm-svn: 283800
This is equivalent to the C++14 std::apply(). Since we are not
using C++14 yet, this allows us to still make use of apply anyway.
Differential revision: https://reviews.llvm.org/D25100
llvm-svn: 283779
This allows you to enumerate over a range using a range-based
for while the return type contains the index of the enumeration.
Differential revision: https://reviews.llvm.org/D25124
llvm-svn: 283337
The CL was originally failing due to the use of some C++14
specific features, so I've removed those. Hopefully this will
satisfy the bots.
llvm-svn: 282867
enumerate allows you to iterate over a range by pairing the
iterator's value with its index in the enumeration. This gives
you most of the benefits of using a for loop while still allowing
the range syntax.
llvm-svn: 282804
This is a little class template that just builds an inheritance chain of
empty classes. Despite how simple this is, it can be used to really
nicely create ranked overload sets. I've added a unittest as much to
document this as test it. You can pass an object of this type as an
argument to a function overload set an it will call the first viable and
enabled candidate at or below the rank of the object.
I'm planning to use this in a subsequent commit to more clearly rank
overload candidates used for SFINAE. All credit for this technique and
both lines of code here to Richard Smith who was helping me rewrite the
SFINAE check in question to much more effectively capture the intended
set of checks.
llvm-svn: 279197