How to get the real and total length of char * (char array)?

Question

For a char [], I can easily get its length by:

char a[] = \"aaaaa\";
int length = sizeof(a)/sizeof(char); // length=6

However,

Answer 1

• In C++:

Just use std::vector which keep the (dynamic) size for you. (Bonus, memory management for free).

Or std::array which keep the (static) size.

• In pure C:

Create a structure to keep the info, something like:

typedef struct {
    char* ptr;
    int size;
} my_array;

my_array malloc_array(int size)
{
    my_array res;
    res.ptr = (char*) malloc(size);
    res.size = size;
    return res;
}

void free_array(my_array array)
{
    free(array.ptr);
}