C++ Diff vector<struct> and a vector<string>?

Question

I track my child processes and their 'title' in my parent process using:

struct c_process {
    string device;
    pid_t pid;
};

vector<c_process> children;

I terminate and fork these children based on if 'folders' exist when I SIGHUP the parent and reload its 'config'.

Parent running
Folders /a1 /a3
Reads config and spawn processes (list of folders)
vector<c_process> = {['a1', 111], ['a3', 222]}
Something changes folders
Folders /a1 /a4 /a5
SIGHUP parent
Reads config and spawn processes
vector<c_process> = {['a1', 111], ['a4', 1121], ['a5', 452]}

My problem occurs when I read the list of folders and need to decide 'what needs to be added/fork' and 'what needs to be 'deleted/terminated'.

vector<string> config;
vector<c_process> c_process;

So with the above structures how can I do this?

Answer 1

Be aware that if std::vector grows and has not enoough space reserved it may allocate and construct new elements via copy constructor from the old ones and afterwards destroy the old ones. If pid_t is some high-level object this may hurt. An alternative is to keep only pointers (may be counting smart pointers) within the vector and therefore avoid the destruction of the refered objects.