string find_first_of fails

why does this fail (VC6 on W2K)

Code:

---

#include <string>

int main()
{
  string spath = "\\windows\\something";

  if(spath.find_first_of("*?") >= 0)
  {
      // this is always true
      // remove the wild cards
  }
}

---

But this works ok:

Code:

---

#include <string>
int main()
{
  string spath = "\\windows\\something";
  int pos = spath.find_first_of("*?");
  if(pos >= 0)
  {
      // remove the wild cards
  }
}

---

find_first_of returns type of size_type, which looks like it's unsigned int. Of course it's always >= 0. In the second example, you are casting it to an int.

Jeff

When using std::string search/find functions, if not found
a special value is returned ... string::npos

So your check should look like this :

Code:

---

#include <string>
#include <iostream>

int main()
{
    std::string spath = "\\windows\\something";

    if(spath.find_first_of("*?") != std::string::npos)
    {
      std::cout << "found wildcard" << std::endl;
    }

    // edit adding further clarification ...


  int pos1 = spath.find_first_of("?*");
  cout << "as an int : " << pos1 << endl;

  string::size_type pos2 = spath.find_first_of("?*");
  cout << "as a string::size_type : " << pos2 << endl;

  cout << "string::npos = " << string::npos << endl;


  return 0;
}

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