I had written this function with the following driver program and output:

`#understand `
#understand
#understand
// Iteration forward from beginning to end by size N.
model
void for_each_by_n (container && cont, function f, unbound_by unsigned = 1) {
if (increment_by == 0) returns; // must check this without op
using std :: begin;
auto it = begin (cont);
using std :: end;
auto end_it = end (cont);
while (it! = end_it) {
in shape);
for (unsigned n = 0; n <increment_by; ++ n) {
if (it == end_it) return;
++ le;
}
}
}
int main () {
std :: array arr {0,1,2,3,4,5,6,7};
std :: vector with {1.2, 1.5, 1.9, 2.5, 3.3, 3.7, 4.2, 4.8};
auto l = [](auto & v) {std :: cout << v << & # 39 ;; };
for_each_by_n (arr, l); std :: cost << & # 39; n & # 39;
for_each_by_n (vec, l); std :: cost << & # 39; n & # 39;
for_each_by_n (arr, l, 2); std :: cost << & # 39; n & # 39;
for_each_by_n (arr, l, 4); std :: cost << & # 39; n & # 39;
for_each_by_n (vec, l, 3); std :: cost << & # 39; n & # 39;
for_each_by_n (vec, l, 5); std :: cost << & # 39; n & # 39;
for_each_by_n (arr, l, 8); std :: cost << & # 39; n & # 39;
for_each_by_n (vec, l, 8); std :: cost << & # 39; n & # 39;
// check the mental health to see if it is not going well.
for_each_by_n (arr, l, 9); std :: cost << & # 39; n & # 39;
for_each_by_n (vec, l, 9); std :: cost << & # 39; n & # 39;
returns 0;
}

*-Exit-*

```
0 1 2 3 4 5 6 7
1,2 1,5 1,9 2,5 3,3 3,7 3,7 4,2 4,8
0 2 4 6
0 4
1,2 2,5 4,2
1,2 3,7
0
1.2
0
1.2
```

While I was giving an answer to this question / answer. I did my best to check for any bugs, corner cases, etc.

What I would like to know about my function above:

- Does this follow modern C ++ standards?
- Is there room for improvement?
- Have I forgotten possible bugs that I may have forgotten?
- Would this be considered legible, reliable, generic, portable, multiplatform and reusable?
- Do I have to worry about the accuracy of const, type deduction, cache errors, etc.?
*-Note-*: I know that the function above is not in a designated namespace, it does not concern us here. I can do it without hassle or trouble.

Let me know what you think; I look forward to receiving all your comments.

I would like to know in advance because I am thinking of adding a second `unsigned integer`

parameter to this function. This would allow the user to choose the index location that he wishes to use for his starting position. This parameter as would also have a default value but in this case it would be 0.