C++ Lecture 8

#ifndef LIST_H
# define LIST_H

class List {
    struct ListLink {
        ListLink(int v) : val(v), next(0) { }
        int val;
        ListLink *next;
    };

public:
    typedef struct ListLink *Iterator;

    List();
    List(const List &ic);
    ~List();
    Iterator getIterator() const;
    bool getNext(Iterator &iter, int &val)
        const;
    void add(int val);
    bool remove(const int &val);
    void removeAll();

private:
    ListLink *head;
    ListLink *tail;
};

#endif /* LIST_H */

// ...

bool
List::getNext(Iterator &iter, int &val) const {
    if (!iter)
        return false;
    val = iter->val;
    iter = iter->next;
    return true;
}


void
List::add(int val)
{
    ListLink *n = new ListLink(val);
    if (tail)
        tail->next = n;
    else
        head = tail = n;
    tail = n;
}

#ifndef LIST_H
# define LIST_H

template <class T>
class List {
    struct ListLink {
        ListLink(T v) : val(v), next(0) { }
        T val;
        ListLink *next;
    };

public:
    typedef struct ListLink *Iterator;

    List();
    List(const List &ic);
    ~List();
    Iterator getIterator() const;
    bool getNext(Iterator &iter, T &val)
        const;
    void add(T val);
    bool remove(const T &val);
    void removeAll();

private:
    ListLink *head;
    ListLink *tail;
};

#endif /* LIST_H */

// ...

template <class T>
bool
List<T>::getNext(Iterator &iter, T &val) const
{
    if (!iter)
        return false;
    val = iter->val;
    iter = iter->next;
    return true;
}


template <class T>
void
List<T>::add(T val)
{
    ListLink *n = new ListLink(val);
    if (tail)
        tail->next = n;
    else
        head = tail = n;
    tail = n;
}

Streams and Formatting: methods

• width(int w): set the width
  width(): get the current width
  • field width of next number or char * (not char);
    may be used by user defined output operators.
  • effects next output only
  • width of 0 means as many as needed (the default)

• precision(int): set the precision
  precision(): get the current precision
  • sets precision of floating point numbers (how many digits to print)
  • default is 6
• fill(char c): set
  fill(): get
  • sets fill character used to pad out fields (default is space)
• flags(ios::fmtflags f): set
  flags(): get
  • sets the format flags to f
  • possible flags (can be or'd together):

     ios::left  ios::right  ios::internal
    
     ios::dec  ios::oct  ios::hex
    
     ios::scientific  ios::fixed
    
     ios::showbase  ios::showpos  ios::uppercase
    	       

• setf(ios::fmtflags f)
  • or f into the existing flags
• setf(ios::fmtflags f, ios::fmtflags mask)
  • clear the mask bits, set the f bits
  • mask values are
    • ios::adjustfield - left, right, internal
    • ios::basefield - dec, oct, hex
    • ios::floatfield - scientific, fixed
• unsetf(ios::fmtflags f)
  • clear the flags from the existing flags

Streams and Formatting: manipulators

• need to
    #include <iomanip.h>
  to use manipulators
• Example:
  cout.width(10);
  cout << i << "\n";
  vs
  cout << setw(10) << i << endl;
• ostream manipulators are:

  endl  ends  flush
  
  oct  dec  hex
  
  			equivalent method
  setw(int w)			width(w)
  setprecision(int n)		precision(n)
  setfill(int c)			fill(c)
  setiosflags(ios::fmtflags f)	setf(f)
  resetiosflags(ios::fmtflags f)	setf(0, f)
  

• istream manipulators are:
  ws - skip white space