Destinguish between numbers and words

I have a text file with numbers and words, and I want to read only the numbers (double)and place then into a vector.

How can I do this?

So far I have

Code:

---

double x;
    while (input >> x) // put input from file into vector
  {
          if (!(input >> x))
          {
              cout << "error - word" << endl;
          }
          else
              input_vec.push_back (x); 
  }

---

stringstreams are always a good option:

Code:

---

#include <fstream>
#include <sstream>
#include <string>
#include <vector>

int main( void ) {
  std::ifstream in( "test.txt" );

  if ( !in )
    return 1;

  double number;
  std::string str;
  std::vector<double> vd;

  while ( in >> str ) {
    std::stringstream ss(str);

    if ( ss >> number )
      vd.push_back( number );
  }

  in.close();

  return 0;
}

---

Probably bugs in there ... didn't compile it.

>How can I do this?
Probably something like this:

Code:

---

std::string word;
double x;

for ( ; ; ) {
  if ( !( std::cin>> x ) ) {
    // Try to skip a word
    if ( !( std::cin>> word ) ) {
      // Input error
      break;
    }
  }
  else
    input_vec.push_back ( x );
}

---

Make sure to call input.clear() if the read fails and you are re-using the stream, otherwise all the subsequent reads will fail.