vector intern

[µ$µ]

wo finde ich, wie vector von STL intern genau arbeitet?

[Ponto]

µ$µ schrieb:

wo finde ich, wie vector von STL intern genau arbeitet?

Im Quellcode. Die vector include ist ein guter Anfang.

[Erhard Henkes]

z.B. auch durch eigene Experimente mit einer eigenen "Verräterklasse":

#define _TEST_
#include <windows.h>
#include <conio.h>
#include <iostream>

/*
 0    BLACK,
 1    BLUE,
 2    GREEN,
 3    CYAN,
 4    RED,
 5    MAGENTA,
 6    BROWN,
 7    LIGHTGRAY,
 8    DARKGRAY,
 9    LIGHTBLUE,
10    LIGHTGREEN,
11    LIGHTCYAN,
12    LIGHTRED,
13    LIGHTMAGENTA,
14    YELLOW,
15    WHITE
*/

void textcolor(WORD color) 
{ 
    SetConsoleTextAttribute(::GetStdHandle(STD_OUTPUT_HANDLE), color); 
} 

const int farbe1 =  3;
const int farbe2 = 15;

class Xint
{
private:
  int num;  
  static int countCtor;
  static int countDtor;  
  static int countCopycon;  
  static int countOpAssign;  
public:
  Xint()
  {
      #ifdef _TEST_  
      textcolor(farbe1); 
      std::cout << this << ": " << "ctor" << std::endl;  
      textcolor(farbe1); 
      #endif
      ++countCtor;
  }

 ~Xint()
  {
      #ifdef _TEST_ 
      textcolor(farbe1);  
      std::cout << this << ": " << "dtor" << std::endl;
      textcolor(farbe2);
      #endif      
      ++countDtor;
  }

  Xint(const Xint& x)
  {
      #ifdef _TEST_
      textcolor(farbe1);  
      std::cout << this << ": " << "copycon von " << std::dec << &x << std::endl;
      textcolor(farbe2);
      #endif  
      num = x.getNum();
      ++countCopycon;
  }

  Xint& operator=(const Xint& x)
  {
      if (&x == this)
      {
          #ifdef _TEST_
          textcolor(farbe1);            
          std::cout << "Selbstzuweisung mit op=" << std::endl;
          textcolor(farbe2);
          #endif
      }
      #ifdef _TEST_
      textcolor(farbe1);
      std::cout << this << ": " << "op= von " << std::dec << &x << std::endl; 
      textcolor(farbe2);
      #endif
      num = x.getNum();
      ++countOpAssign;
      return *this;
  }
  int getNum() const {return num;}
  void setNum(int val) {num = val;}
  static void statistik(std::ostream&);
  static void reset();
};

int Xint::countCtor     = 0;
int Xint::countDtor     = 0;  
int Xint::countCopycon  = 0;  
int Xint::countOpAssign = 0;  

void Xint::statistik(std::ostream& os)
{
  textcolor(farbe1);  
  os   << "Ctor:    " << countCtor    << std::endl 
       << "Dtor:    " << countDtor    << std::endl
       << "Copycon: " << countCopycon << std::endl
       << "op=:     " << countOpAssign;   
  textcolor(farbe2);     
}    

void Xint::reset()
{
    countCtor     = 0;
    countDtor     = 0;  
    countCopycon  = 0;  
    countOpAssign = 0;  
} 

std::ostream& operator<< (std::ostream& os, const Xint& x) 
{
  os << x.getNum();
  return os;
}

bool operator< (const Xint& a, const Xint& b) 
{
    return a.getNum() < b.getNum(); 
}

bool operator> (const Xint& a, const Xint& b) 
{
    return a.getNum() > b.getNum(); 
}

bool operator== (const Xint& a, const Xint& b) 
{
    return a.getNum() == b.getNum(); 
}

bool operator!= (const Xint& a, const Xint& b) 
{
    return a.getNum() != b.getNum(); 
}

/***********************************************************/

#include <vector>
using namespace std;

int main()
{
  const char NL = '\n';
  const int  N  = 2;
  X x;
  cout << NL;
  vector<X> v;
  cout << "Size:     " << v.size() << NL;  
  cout << "Capacity: " << v.capacity() << NL;    
  cout << NL;
  v.reserve(N);
  cout << "Size:     " << v.size() << NL;  
  cout << "Capacity: " << v.capacity() << NL;    
  cout << NL;
  for(size_t i=0; i<N; ++i) v.push_back(x);
  cout << NL;
  cout << "Size:     " << v.size() << NL;  
  cout << "Capacity: " << v.capacity() << NL;     
  for(size_t i=0; i<v.capacity(); ++i) cout << &v[i] << ": " << v[i].getNum() << NL;    
  cout << NL;
  x.setNum(333);
  for(size_t i=0; i<N; ++i) v[i]=x;
  cout << NL;
  cout << "Size:     " << v.size() << NL;  
  cout << "Capacity: " << v.capacity() << NL;      
  for(size_t i=0; i<v.capacity(); ++i) cout << &v[i] << ": " << v[i].getNum() << NL;    
  cout << NL;
  vector<X>::iterator it = v.begin()+1;
  x.setNum(911);
  v.insert(it,x);
  cout << NL;
  cout << "Size:     " << v.size() << NL;  
  cout << "Capacity: " << v.capacity() << NL;    
  for(size_t i=0; i<v.capacity(); ++i) cout << &v[i] << ": " << v[i].getNum() << NL;    

  cin.get();
}

0x22ff58: ctor

Size:     0
Capacity: 0

Size:     0
Capacity: 2

0x3f2528: copycon von 0x22ff58
0x3f252c: copycon von 0x22ff58

Size:     2
Capacity: 2
0x3f2528: 42
0x3f252c: 42

0x3f2528: op= von 0x22ff58
0x3f252c: op= von 0x22ff58

Size:     2
Capacity: 2
0x3f2528: 333
0x3f252c: 333

0x3f25c8: copycon von 0x3f2528
0x3f25cc: copycon von 0x22ff58
0x3f25d0: copycon von 0x3f252c
0x3f2528: dtor
0x3f252c: dtor

Size:     3
Capacity: 4
0x3f25c8: 333
0x3f25cc: 911
0x3f25d0: 333
0x3f25d4: 1142973805