DaniWeb Forum Index > Software Development > C

C RSS

STL find_if

Please support our C advertiser: Programming Forums - DaniWeb Sister Site

•

Join Date: Jul 2005

Posts: 472

Reputation: MIGSoft is an unknown quantity at this point

Solved Threads: 1

MIGSoft

Offline

Posting Pro in Training

STL find_if

Mar 18th, 2007

Hey everybody,
Could somebody please provide an example for using the STL find_if for the following task. I am trying to search a vector of structs, using the following criteria: compare whether the key of the struct in the vector matches the key of another struct (instace of the same type of struct) that I want to find. So basically search the vector for a particular struct. I want to use find_if, in order to replace the handwritten routine I have now. I have seen many complex, examples online. If anybody knows of simple and clean way, please share. Thanks in advance.

•

Join Date: Aug 2005

Posts: 5,266

Reputation: iamthwee is a splendid one to behold

Solved Threads: 377

iamthwee

Offline

Posting Expert

Re: STL find_if

Mar 19th, 2007

Loop through the vector of objects, if that object matches the one in hand return a success message?

*Voted best profile in the world*

•

Join Date: Dec 2006

Posts: 1,089

Reputation: vijayan121 is a name known to all

Solved Threads: 164

vijayan121 vijayan121 is offline

Offline

Veteran Poster

Re: STL find_if

Mar 20th, 2007

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <vector>
#include <algorithm>
 
struct some_struct { int key ; /* ... */ };
 
struct has_same_key
{
  explicit ( const some_struct& s ) : what(s) {}
  bool operator() ( const some_struct& elem ) const
  { return elem.key == what.key ; }
  const some_struct& what ;
};
 
inline std::vector<some_struct>::const_iterator 
   do_find( const std::vector<some_struct>& vec, const some_struct& what )
{
  return std::find_if( vec.begin(), vec.end(), has_same_key(what) ) ;
}
#include <vector>
#include <algorithm>

struct some_struct { int key ; /* ... */ };

struct has_same_key
{
  explicit ( const some_struct& s ) : what(s) {}
  bool operator() ( const some_struct& elem ) const
  { return elem.key == what.key ; }
  const some_struct& what ;
};

inline std::vector<some_struct>::const_iterator 
   do_find( const std::vector<some_struct>& vec, const some_struct& what )
{
  return std::find_if( vec.begin(), vec.end(), has_same_key(what) ) ;
}