Syntax:

    #include <string>
    size_type find_first_of( const string &str, size_type index = 0 );
    size_type find_first_of( const char* str, size_type index = 0 );
    size_type find_first_of( const char* str, size_type index, size_type num );
    size_type find_first_of( char ch, size_type index = 0 );

The find_first_of() function either:

* returns the index of the first character within the current string that

  matches any character in str, beginning the search at index, string::npos if
  nothing is found,

  characters in str, returning the index in the current string of the first
  character found, or string::npos if no characters match,

  starting the search at index, string::npos if nothing is found.

Related Topics: find, find_first_not_of, find_last_not_of, find_last_of, rfind