This is a breaking change as it makes Async a template (e.g. Async<> must
be used instead of just Async). When data parameters are provided, an
internal mutex and vector is used to hold the parameter packs until the loop
runs.
This optimizes the common case of a single simple callback (e.g. std::function
or lambda) so no additional allocation is required. As a Connection return
value is not possible in this case, provide a separate connect_connection()
function to provide that.
Imported from https://github.com/palacaze/sigslot
Classes were renamed from lowercase_me to UppercaseMe style, primarily
to avoid conflicting with the C standard library "signal" function. They
were also moved to the "wpi::sig" namespace.
The anonymous namespace was renamed due to -Wsubobject-linkage complaining
about a field created in a GTest template class (CborRoundtripTestParam)
being defined in an anonymous namespace. See
https://stackoverflow.com/a/37723265.
During shared library loading, a different libLLVM can be pulled in, causing
llvm symbols from dependent libraries to resolve to that library instead of
this one. This has been seen in the wild with the Mesa OpenGL implementation
in JavaFX applications (see wpilibsuite/shuffleboard#361).
This is clearly a very breaking change. For some level of backwards
compatibility, a namespace alias from llvm to wpi is performed in the "llvm"
headers. Unfortunately, forward declarations of llvm classes will still break,
but compilers seem to generate clear error messages in those cases
("namespace alias 'llvm' not allowed here, assuming 'wpi'").
This change also moves all the wpiutil headers to a single "wpi" subdirectory
from the previously split "llvm", "support", "tcpsockets", and "udpsockets".
Shim headers will be added for backwards compatibility in a later commit.
