c++ - Increment pointer returned by function -

hey experimenting bit c/c++ , pointers while reading stuff here

i made myself function return pointer int @ place in global array.

int vals[] = { 5, 1, 45 };  int *  setvalue(int k) {     return &vals[k]; }

however able this

int* j = setvalue(0); j++; *j = 7;

to manipulate array

but that:

*(++setvalue(0)) = 42;

din't work. notice *setvalue(0) = 42; works

from understand call function , pointer increment make point 2nd element in array. lastly deference pointer , assign new value integer pointed to.

i find c++ pointers , references can confusing maybe can explain me behavior.

edit: question not duplicate of increment, preincrement , postincrement

because not pre- vs. post-increment rather increment on pointers return of function.

edit2:

tweaking function

int **  setvalue(int k) {     int* x = &vals[k];     return &x; }

you can use

*(++(*setvalue(1))) = 42;

you can't call unary operator (++) on not variable. setvalue(0) treated value.

so,

*(setvalue(0)++) = 42;

should be

*(setvalue(0) + 1) = 42;

Shefl