Can anyone tell me how to validate ip address

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <iterator>

using namespace std;

// You won't need this
typedef char TCHAR;

vector<string> split(TCHAR* str, TCHAR delimiter)
{
    const string data(str);
    vector<string> elements;

    string element;
    for(int i = 0; i < data.size(); ++i)
    {
        if (data[i] == delimiter)
        {
            elements.push_back(element);
            element.clear();
        }
        else
            element += data[i];
    }
    elements.push_back(element);
    return elements;
}

bool toInt(const string& str, int* result)
{
    if (str.find_first_not_of("0123456789") != string::npos)
        return false;

    stringstream stream(str);
    stream >> *result; // Should probably check the return value here
    return true;
}

bool validate(TCHAR* ip)
{
    const static TCHAR delimiter = '.';
    const vector<string> parts = split(ip, delimiter);
    if (parts.size() != 4)
        return false;

    for(int i = 0; i < parts.size(); ++i)
    {
        int part;
        if (!toInt(parts[i], &part))
            return false;
        if (part < 0 || part > 255)
            return false;
    }
    return true;
}

int main()
{
    cout << validate("13.23.12.221") << endl;
    return 0;
}