Explain how this C++ function returns an array -

i found code online http://www.cplusplus.com/forum/beginner/6644/#msg30551 supposed return array c++ function. explanation illustrating how function operates respect memory allocation, stacks, heaps, pointers etc.

int *f(size_t s){     int *ret=new int[s];     (size_t a=0;a<s;a++)         ret[a]=a;     return ret; } 

i.

int *ret=new int[s]; 

1. allocate memory ret on stack - int pointer
2. allocate continuous memory size s * sizeof(int) on heap
3. make ret point first element of allocated memory (from 2.)

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ii.

for (size_t a=0;a<s;a++)     ret[a]=a; 

1. allocates memory on stack a
2. loop through allocated memory in i., assigning values each element
3. after end of for-statement, a no longer accessible (it's available in for)

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iii.

return ret; 

return a copy of ret pointer, points first element of created in i. array, initialized in ii.

after return, ret "destroyed".

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the caller of function must not forget deallocate (free) memory, invoking delete[].

for example:

int * my_array = f( 6 ); // sth my_array delete[] my_array;