C++ 中对vector<T*> 数组的查找和排序

//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
#include <vector>
#include <algorithm>
using namespace std;
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;

class CA
{
public:
    int a;

    CA(int a)
    {
        this->a = a;
    }

    bool operator == (int t)
    {
        return a == t;
    }
    //无法编译
    //friend bool operator == (const CA* ca,int t);
};
//无法编译
/*
bool operator == (const CA* ca,int t)
{
    return ca->a == t;
}*/


bool Compare(CA* f, CA* s)
{
    return f->a < s->a;
}

template<class T1,class T2>
vector<T1*>::iterator Find( vector<T1*>::iterator begin,
                            vector<T1*>::iterator end,
                            const T2& var)
{
    while(begin != end)
    {
        if (*(*begin) == var)
        {
            return begin;
        }
        begin++;
    }
}


template<class T1,class T2>
vector<T1*> FindRange( vector<T1*>::iterator begin,
                       vector<T1*>::iterator end,
                       const T2& var)
{
    vector<T1*> result;
    while(begin != end)
    {
        if (*(*begin) == var)
        {
            result.push_back(*begin);
        }
        begin++;
    }
    return  result;
}

/***
 * 使用find_if
 */
static int globA = 1;

bool prec (CA* ca)
{
    if (globA == ca->a)
        return true;
    else
        return false;
}

vector<CA*> arry;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
    : TForm(Owner)
{
    arry.push_back(new CA(2));
    arry.push_back(new CA(21));
    arry.push_back(new CA(3));
    arry.push_back(new CA(1));
    arry.push_back(new CA(4));
    arry.push_back(new CA(1));
    arry.push_back(new CA(12));
}
//---------------------------------------------------------------------------


void __fastcall TForm1::Button1Click(TObject *Sender)
{
    sort(arry.begin(),arry.end(),Compare);
    for(unsigned i = 0; i < arry.size(); i++)
    {
        ShowMessage(IntToStr(arry[i]->a));
    }

    vector<CA*>::iterator itor = find(arry.begin(),arry.end(),21);
    if (itor != arry.end())
    {
        ShowMessage("find!");
    }


    vector<CA*> range = FindRange<CA,int>(arry.begin(),arry.end(),1);
    ShowMessage("find "+IntToStr(range.size())+" number");

    globA = 1;
    vector<CA*>::iterator itor2 = find_if(arry.begin(),arry.end(),prec);
    if (itor2 != arry.end())
    {
        ShowMessage("find!");
    }
}
//---------------------------------------------------------------------------
void __fastcall TForm1::FormDestroy(TObject *Sender)
{
    for (unsigned i =0; i < arry.size() ;i++)
    {
        delete arry[i];
        arry[i] = NULL;
    }
    arry.clear();
}
//---------------------------------------------------------------------------

template <class _RandomAccessIter, class _Tp>
_STLP_INLINE_LOOP _RandomAccessIter __find(_RandomAccessIter __first, _RandomAccessIter __last,
                                           const _Tp& __val,
                                           const random_access_iterator_tag &)
{
  _STLP_DIFFERENCE_TYPE(_RandomAccessIter) __trip_count = (__last - __first) >> 2;

  for ( ; __trip_count > 0 ; --__trip_count) {
    if (*__first == __val) return __first; //解除引用然后比较
    ++__first;

    if (*__first == __val) return __first;
    ++__first;

    if (*__first == __val) return __first;
    ++__first;

    if (*__first == __val) return __first;
    ++__first;
  }

  switch(__last - __first) {
  case 3:
    if (*__first == __val) return __first;
    ++__first;
  case 2:
    if (*__first == __val) return __first;
    ++__first;
  case 1:
    if (*__first == __val) return __first;
    ++__first;
  case 0:
  default:
    return __last;
  }
}

//自己实现一个Find泛型方法，不过依然要求实现操作符重载。
template<class T1,class T2>
vector<T1*>::iterator Find( vector<T1*>::iterator begin,
                            vector<T1*>::iterator end,
                            const T2& var)
{
    while(begin != end)
    {
        if (*(*begin) == var)
        {
            return begin;
        }
        begin++;
    }
}

template <class _RandomAccessIter, class _Predicate>
_STLP_INLINE_LOOP _RandomAccessIter __find_if(_RandomAccessIter __first, _RandomAccessIter __last,
                                              _Predicate __pred,
                                              const random_access_iterator_tag &)
{
  _STLP_DIFFERENCE_TYPE(_RandomAccessIter) __trip_count = (__last - __first) >> 2;

  for ( ; __trip_count > 0 ; --__trip_count) {
    if (__pred(*__first)) return __first;
    ++__first;

    if (__pred(*__first)) return __first;
    ++__first;

    if (__pred(*__first)) return __first;
    ++__first;

    if (__pred(*__first)) return __first;
    ++__first;
  }

  switch(__last - __first) {
  case 3:
    if (__pred(*__first)) return __first;
    ++__first;
  case 2:
    if (__pred(*__first)) return __first;
    ++__first;
  case 1:
    if (__pred(*__first)) return __first;
    //    ++__first;  我不知道为什么这里有这样的注释，C++ BUILDER 6 里面的代码就是这样的。可见，标准库也是人写的。
  case 0:
  default:
    return __last;
  }
}

/***
 * 使用find_if
 */
static int globA = 1;

bool prec (CA* ca)
{
    if (globA == ca->a)
        return true;
    else
        return false;
}
//使用时
globA = 1;
vector<CA*>::iterator itor2 = find_if(arry.begin(),arry.end(),prec);