df0b363cf0
This is a reland of commit 9e4a97bb02663604b02e219b9d501a8dd91b5614 Original change's description: > [Stats] Add value_or() and migrate from ValueOrDefault(). > > Yet another prerequisite for replacing RTCStatsMember<T> with > absl::optional<T>, but this looks like the last one. > > Bug: webrtc:15164 > Change-Id: I2cde51e8c8c951f71b48ccd45e07146091a99616 > Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/334647 > Commit-Queue: Henrik Boström <hbos@webrtc.org> > Reviewed-by: Harald Alvestrand <hta@webrtc.org> > Cr-Commit-Position: refs/heads/main@{#41541} Bug: webrtc:15164 Change-Id: I5fdba499383e5d9efe0a1dcef6bf6c2e0a812857 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/335102 Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Reviewed-by: Henrik Boström <hbos@webrtc.org> Cr-Commit-Position: refs/heads/main@{#41564}
How to write code in the api/ directory
Mostly, just follow the regular style guide, but:
- Note that
api/code is not exempt from the “.hand.ccfiles come in pairs” rule, so if you declare something inapi/path/to/foo.h, it should be defined inapi/path/to/foo.cc. - Headers in
api/should, if possible, not#includeheaders outsideapi/. It’s not always possible to avoid this, but be aware that it adds to a small mountain of technical debt that we’re trying to shrink. .ccfiles inapi/, on the other hand, are free to#includeheaders outsideapi/.- Avoid structs in api, prefer classes.
The preferred way for api/ code to access non-api/ code is to call
it from a .cc file, so that users of our API headers won’t transitively
#include non-public headers.
For headers in api/ that need to refer to non-public types, forward
declarations are often a lesser evil than including non-public header files. The
usual rules still apply, though.
.cc files in api/ should preferably be kept reasonably small. If a
substantial implementation is needed, consider putting it with our non-public
code, and just call it from the api/ .cc file.
Avoid defining api with structs as it makes harder for the api to evolve. Your struct may gain invariant, or change how it represents data. Evolving struct from the api is particular challenging as it is designed to be used in other code bases and thus needs to be updated independetly from its usage. Class with accessors and setters makes such migration safer. See Google C++ style guide for more.
If you need to evolve existent struct in api, prefer first to convert it into a class.