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10694 :: creating nimstring using pre-allocated buffer to prevent copy

• alireza (orginal) [2023-11-28T04:38:24+01:00] view original

  Hi, I was wondering what can go wrong (and how to fix/prevent it ofc) if i create a nim string out of my own buffer which I have preallocated using alloc()

  The reason I do this is ofc copy prevention. And the way I create that string is exactly like system/strs_v2.nim i only set the pointer to my own buffer.

  My own guess is the after free problem, but sample code I wrote for my self currently passes basic string tests...

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• Araq (orginal) [2023-11-28T06:48:41+01:00] view original

  It is possible to do that if you set the strlitFlag flag. I've recently discovered the same trick, strange how these things work...

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• termer (orginal) [2023-11-29T07:07:15+01:00] view original

  This isn't exactly what you're asking for, but if you just want something with a fixed size or capacity that is resistant to copying issues and heap-related bugs, I wrote a library called stack_strings that has a fixed-sized stack-allocated buffer and string heuristics. You can get a pointer to the data and use it as a cstring or array and compare that. If none of that is useful or important to your question, then please disregard.

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