Extension to the STL “find_if” and “for_each”

The stl algorithms for_each and find_if are inadequate when
you need more data for the predicate. Here are two new algorithms
TDfind_if and TDfor_each which solve that problem.

To use:

std::list<OBJECT> theList;

class DATA
{
public:
    bool IsValid(const OBJECT& rObject) const;
    void OperateOn(OBJECT& rObject) const;
};

bool IsValid(OBJECT theObject, DATA theData)
{
    return theData.IsValid(theObject);
}

void DoOperation(OBJECT theObject, DATA theData)
{
    theData.OperateOn(theObject);
}

DATA theData;

OBJECT theObject = ::TDFind_if(theList.begin(), theList.end(), IsValid, theData);
or
::TDfor_each(theList.begin(), theList.end(), DoOperation, theData);

// CODE STARTS HERE:
/////////////////////////////////////////////////////////////////
// This is like the Standard c++ algorithm find_if, but it takes a second parameter
template<class _II, class _Pr, class T_DATA> inline
_II
TDfind_if(
  _II _F, // First iterator
  _II _L, // Last iterator
  _Pr _P, // Predicate: a static function that returns bool having two
paramters
  T_DATA dwData)
{
    for (; _F != _L; ++_F)
    {
        if (_P(*_F, dwData))
        {
            break;
        }
    }

    return (_F);
}


template<class _II, class _Fn, class T_DATA> inline
void
TDfor_each(
  _II _F,
  _II _L,
  _Fn _Op,
  T_DATA dData)
{
    for (; _F != _L; ++_F)
    {
        _Op(*_F, dData);
    }
}

Date Posted: 5/4/98

Posted by: Pat Laplante.