you can also have something akin to MIDI encoding with higher bit reserved to mark that next byte is a part of length field, too. up to 128 bytes with no overhead, up to 16kb with one byte overhead, and so on. Such a detail would be easy to hide in the library. But I wouldn't be surprised that alignment and other troubles would eat any possible gain.

> But I wouldn't be surprised that alignment ... troubles would eat any possible gain.

It's string. Alignment shouldn't be a problem. Rather alignment issues are for the pointers to that string.

Won't work with UTF-8.

Works with any encoding and arbitrary binary data. The last byte of the length field doesn't have the high bit set, and whatever follows after that is completely irrelevant.

But still needless complexity for this.

Sure it is, the length is out of band. In fact, you could even use utf-8 to encode the length!

Don't forget supporting small strings (<= 7 bytes) in the pointer itself using tag bits. No allocation or dereferencing required.

Microsoft's MFC used to do this in their first version. But later ditched it. Maybe they found it not worth the trouble of checking for this condition everywhere. Increase in code.

Thse days, in C++, this is routinely done in various std::string implementations (which are both null terminated and have a separate length). In fact the standard was updated to explicitly allow this.