Comment by none_to_remain
16 days ago
The size overhead of that is 2*sizeof(int) while the overhead of null termination is sizeof(char). If I remember the standard right, the former is worse by at least sizeof(char), and usually more in practice. This used to matter, sometimes still does.
I would assume the difference is mostly negligible in practice due to the allocator rounding up the allocated memory size at least by the word size anyway (for alignment and simpler bookkeeping). You can also use variable-length encoding in the header to use 1 byte for most cases, similar to how UTF-8 does it: if the most significant bit is not set, we assume a 7-bit encoding, which can represent string lengths up to 127 using 1 byte, which is probably 99% of strings.
Well, not saying to always use it, but if the string size is big enough, the overhead of 2 ints becomes relatively vanishing. For generic dynamically sized strings it probably has more advantages than disadvantages. But in any case, sure, if every single byte matters or some structure requires specific memory layout, then fine. I just don't think these things are the majority of use cases. Keep in mind that the cached lengths can increase performance, since you don't have to recalculate string lengths.
> Well, not saying to always use it, but if the string size is big enough, the overhead of 2 ints becomes relatively vanishing.
In that case, the fix is not to change C strings (breaking a lot of existing code), but to introduce a stringbuilder type.
You can still use null terminator for compatibility (std::string does use this), but just not rely on that in your own code.
I am a terrible hobby c programmer that doesn't understand pointers but surely a symmetric approach doesn't have the overhead or the bug. that is to say that if the language was designed to work in single bit pairs of a string character in conjunction of a string length character assuming a fail safe design of one dummy string character then if a bug happens in the code then there's no overflow because the length can never be shorter than the character.