如何遍历具有struct指针的向量？

struct some_struct{
     some_struct *pointer_to_another_struct;
     int a;
some_struct(int value ) :a (value), pointer_to_another(NULL)()
};

...

vector<some_struct *> tree;
...

for ( auto it = tree.begin(); it != tree.end();  ++it) {
     it->a=10;
}
struct some_struct{
     some_struct *pointer_t