This reimplements our comparison functions as C++ Comparators and then provides compatibility shims for interoperating with existing Objective-C usage.
A few specialized comparators aren't suitable for porting but only have a single usage (e.g. CompareBytes for comparing NSData * instances). In these cases I've moved them into the caller.
* Use int32_t for typeof(ID) in FSTDocumentReference
* Migrate callers of FSTComparison.h to Objective-C++
* Port comparison to C++
* Migrate usages of FSTComparison.h to C++ equivalents
* Remove FSTComparison
* Port StringPrintf from //base.
Prefer this to approaches based on variadic templates. While the variadic
template mechanisms are strictly safer, they result in binary bloat we
can't afford.
This is essentially the same StringPrintf previously open sourced as a
part of protobuf, though updated for C++11 which saves a copy and a
temporary buffer on the heap.
* Add abseil as a subdirectory of Firestore
This saves having to redefine all the libraries that abseil defines as
imported libraries.
* Rename firebase_firesture_util_log_* targets
Cut the log out of the name to reflect that these will get more
components besides just logging.
Marek Gilbert