• ZILtoid1991@lemmy.worldOP
      71·
      4 months ago

      The & operator references the value.

      int i;
int* p = &i;

      In C++, the & at the function argument makes it a reference type (safe pointer).

      void someFunction(int& refVal) {
    [...]
}
      • Flames5123@sh.itjust.worksEnglish
        32·
        4 months ago

        As someone who likes working with higher level languages, I never understood the pass by reference or even referencing different pointers. It never stuck out to me as useful in what I want software to do. It’s too close to hardware.

        • Sylvartas@lemmy.dbzer0.comEnglish
          10·
          4 months ago

          Most of the time you pass by reference for more outputs, or by const ref to avoid copying a big-ass data structure (which is not always straightforward, with structures smaller than a pointer, which are pretty big in 64 bits architecture, you lose more to the ref overhead than to the copy IIRC)

          • DahGangalang@infosec.pub
            4·
            4 months ago

            Another reason I commonly see: to change the structure / “main pointer” to a data structure (esp during freeing and cleanup).

        • ZILtoid1991@lemmy.worldOP
          1·
          4 months ago

          Reference values are quite useful, such as:

          double valOut;
if (parseDouble(valOut) == 0) { //Argument of parseDouble is ref type, no & needed for input, no exceptions needed for error handling
    [...] //No error, code executed normally
} else {
    [...] //Erroreus input
}
    • Dejected Warp Core@lemmy.world
      4·
      3 months ago

      *x = dereference or “point to”. Treats the variable x as containing a pointer value. Evaluates to a variable existing at the address in x.

      &x = reference or “get address of”. Evaluates to the address of x.

      They’re complimentary operators, so *(&x) cancels out and is equvalent to just x.