Commit Graph

2 Commits

Author SHA1 Message Date
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Chandler Carruth aa60b3fd87 [ADT] Add llvm::unique_function which is like std::function but
supporting move-only closures.

Most of the core optimizations for std::function are here plus
a potentially novel one that detects trivially movable and destroyable
functors and implements those with fewer indirections.

This is especially useful as we start trying to add concurrency
primitives as those often end up with move-only types (futures,
promises, etc) and wanting them to work through lambdas.

As further work, we could add better support for things like const-qualified
operator()s to support more algorithms, and r-value ref qualified operator()s
to model call-once. None of that is here though.

We can also provide our own llvm::function that has some of the optimizations
used in this class, but with copy semantics instead of move semantics.

This is motivated by increasing usage of things like executors and the task
queue where it is useful to embed move-only types like a std::promise within
a type erased function. That isn't possible without this version of a type
erased function.

Differential Revision: https://reviews.llvm.org/D48349

llvm-svn: 336156
2018-07-02 23:57:29 +00:00