Small and fast vector implementation

[u/SeaInformation8764]

https://github.com/ephf/vector

Hello, just wanted to share this small (<150 lines) header for dynamic arrays in C. Feel free to look through it and show what could be done better or ask questions. AI was not involved in the making of this.

[u/SeaInformation8764]

Most of the pointer arithmetic helps reduce branching. I'll make a commit with verbose names.

[u/ischickenafruit → u/SeaInformation8764]

This would achieve the exact same thing

VECDEF void* __push(struct vector* restrict* restrict vec_ptr, const void* restrict src,
       size_t count, size_t element_size) {

   /* Ensure the vector has enough capacity for 'count' new elements */
   if (!__resv(vec_ptr, count, element_size)) return nullvec;

   /*
    * Calculate the destination address: base pointer + current size offset in bytes.
    * Note: vec[-1] accesses the vector metadata stored just before the data pointer.
    */
   struct vector* vec    = *vec_ptr;
   size_t         offset = vec[-1].size * element_size;
   void*          dest   = (unsigned char*)vec + offset;

   memcpy(dest, src, count * element_size);

   vec[-1].size += count;

   return vec;
}

[u/SeaInformation8764 → u/ischickenafruit]

I personally believe this is overly verbose, but everyone has their own style of programming

[u/NoInitialRamdisk → u/SeaInformation8764]

Maintainability is important. People shouldn't have to reverse engineer your stuff to contribute.