C++ String Tokenizer

size_t pos = 0;
std::string token;
while ((pos = s.find(delimiter)) != std::string::npos) {
    token = s.substr(0, pos);
    std::cout << token << std::endl;
    s.erase(0, pos + delimiter.length());
}

std::string::npos


static const size_t npos = -1;



Maximum value for size_t

npos is a static member constant value with the greatest possible value for an element of type size_t.

This value, when used as the value for a len (or sublen) parameter in string's member functions, means "until the end of the string".

As a return value, it is usually used to indicate no matches.

This constant is defined with a value of -1, which because size_t is an unsigned integral type, it is the largest possible representable value for this type.
input: 1 2 3 4
vector<int> a;
 string line;
 getline(cin, line);
 size_t pos = 0;

 string token;
 string delimiter = " ";
 while ((pos = line.find(delimiter))!=std::string::npos) {
     token = line.substr(0, pos);
     a.push_back(atoi(token.c_str()));
     line.erase(0, pos + delimiter.length());
 }
 a.push_back(atoi(line.c_str()));