Mostly, just follow the regular style guide, but:
api/code is not exempt from the “
.ccfiles come in pairs” rule, so if you declare something in
api/path/to/foo.h, it should be defined in
api/should, if possible, not
api/. 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.
api/, on the other hand, are free to
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
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.