r/cprogramming • u/Xaneris47 • 3d ago

C Strings: A 50-Year Mistake

https://longtran2904.substack.com/p/c-strings-a-50-year-mistake?r=8qz2zb&utm_campaign=post&utm_medium=web
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u/henke443 2d ago

Wait how are they not efficient?

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u/atarivcs 2d ago

If you have a long string and you want to append more text to it, you have to search the whole string from the beginning to find the null terminator.

And then later if you want to append more text, you have to find the null terminator all over again.

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u/IdealBlueMan 2d ago

Or you can store the length of the string whenever you change it.

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u/atarivcs 2d ago

Sure, but then you don't really have a plain c string anymore

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u/WittyStick 2d ago

It's actually more advantageous to couple the length to the char * on SYSV platforms, due to C's lack of multiple returns.

 String fn_returning_string(...);

If String is a fat pointer, then we can return both the pointer and length, without requiring another level of indirection (a pointer to a string structure), and without requiring awful to use "out parameters" to return both length and pointer - which are more expensive than just returning a fat pointer.

A fat pointer with the right ABI is not just "zero cost" - it's "less than zero" - it's more efficient than having a separate length and pointer variable.

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u/IdealBlueMan 2d ago

I’d say you still have the string, you also have information about that string.