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Transcription

1 C

2 2

3 Contents sizeof union reference static const volatile mutable explicit typedef new & delete class i

4 ii CONTENTS 2.3 static bit-field virtual virtual inheritance RTTI run-time type identification dynamic cast typeid type info template empty size() Standard Template Library (STL) functional function objects Operator classes Adaptor and conversion functions Instrumental types count() count if() vector<bool>?

5 CONTENTS iii iterator const iterator reverse iterator const reverse iterator distance advance const iterator iterator reverse iterator base() iterator remove erase remove

6 iv CONTENTS

7 Chapter ɛ 1.2 #include <ctype.h> : isupper(c), tolower(c) *prt a; *prt b++; // ++(*ptr a); // *(prt b++); = 2. = +1 1

8 2 CHAPTER char char a = 256 ; int d = a ; cout<<d<<endl ; // long double 1. long double long double 2. long double double double 3. double float float 4. 3 int integral promotion char signed char unsigned char short int int unsigned short short 2 int 4 unsigned short int unsigned int wchar t underlying type enum status bad, ok } ; 0 1. char char char status int (a) unsigned long unsigned long

9 (b) unsigned long long long long long unsigned int long unsigned int 32 long int 4 1 unsigned int long unsigned long long unsigned int unsigned int int C++ 4 dynamic cast(expression) dynamic cast safe downcasting static cast(expression) static cast non-const const int double void* const non-const const cast C-style const cast(expression) const cast C++ reinterpret cast(expression) reinterpret cast inplementationdependent 1. grep 2. const cast

10 4 CHAPTER C++ automatic static dynamic sizeof sizeof 4. char str[] = 123 ; // 4 \0 2 4 struct Struct char ch1 ; // 2 short sn ; //2 char ch2 ; // 2 6 sn int 4 12 ch1 ch2 4 sn double 8 16 ch1 ch2 4 struct struct Struct Struct array[2] ; cout<<sizeof array<<endl ; // class B: public virtual A... 4 virtual 4 class A public: A() ; A() ; virtual void f() } 4

11 1.7. SIZEOF 5 sizeof sizeof sizeof(a1) 4 class A1 public: int a ; static int b ; A1() ; A1() ; sizeof strlen 1. sizeof strlen 2. sizeof size t typedef unsigned int 3. sizeof strlen char* \0 sizeof short f() ; cout<<sizeof(f())<<endl ; sizeof(short) 2 4. sizeof strlen 5. sizeof sizeof(x) 6. strlen 7. sizeof sizeof 8. sizeof char s[100] sizeof sizeof 9. sizeof void

12 6 CHAPTER union struct / union test test() } int office; char teacher[5];. a test a.class a.office int main() union int test; char c; test=5; c= a ; std::cout<<i<< <<c ; return 0 ; } (static)

13 = const char * : const char : int (*p)(int, int); : int (*p1)(int,...); int (*p2)(int); int (*(*F)(int,int))(int); F int int int int float(**def)[10]; def float double*(*gh)[10]; gh double* double(*f[10])(); f f 10 double int*((*b)[10]); int* (*b)[10]; int fun(int);, p2=fun;, p2=&fun;

14 8 CHAPTER 1. p2 p2(3); (*p2)(3); reference lvalue x a[i] *ptr int & ra=a, & rb=b; 1.11 alias namespace abc = somelongname; namespace const int SIZE = 64 ; int max ; } 1.12 extern extern int a;

15 1.13. STATIC static static new static static / static static public protected private :: = private public ( ). :: name-mangling static static const const

16 10 CHAPTER 1. nonmember. -> :: 1.14 const const char greeting[]= Hello. // const mutable const const mutable C++ #define const const #define const const const C const bufsize ; C++ C C const C++ const C++ C extern extern const bufsize ; // const const extern

17 1.15. VOLATILE volatile volatile volatile volatile const volatile volatile 1.16 mutable const mutable mutable const 1.17 explicit C++ class MyClass public: MyClass( int num ) ; // constructor and implicit conversion operator... MyClass obj = 10 ; //ok,convert int to MyClass MyClass MyClass temp 10 ; MyClass obj = temp ; explicit MyClass class MyClass public: explicit MyClass( int num ) ;... MyClass obj1 = 10 ; // error,can t non-explict convert MyClass obj2 ; obj2 = 20 ; // error,can t non-explict convert

18 12 CHAPTER 1. explicit 1.18 typedef typedef char * StringArray[]; main(int argc, StringArray argv) // StringArray argv == char * argv[] : typedef char SString[256]; // SString 256 typedef enum TagLink, Thread // Tag enumlink, Thread} 1.19 new & delete int *m=new int[20]; int *j=new(11); // 20 int // 11 new new (ptr) type ptr <new> delete [] arrayname; malloc/free malloc/free malloc/free C++ new delete new/delete 1.20 TP TP TP & const TP

19 signatures TP & const TP & const TP * TP * TP * TP []

20 14 CHAPTER 1.

21 Chapter 2 class 2.1 array-style struct const member-initializer : static 1. static.cpp 2. static this static ClassName:: 3. static 2.4 bit-field bit-field 15

22 16 CHAPTER 2. CLASS class File //... unsigned int modified : 1 ; // modified bit-field 5 unsigned int mode typedef unsigned int Bit ; class File public: Bit mode: 2 ; Bit modified: 1 ; Bit prot owner: 3 ; Bit prot group: 3 ; Bit prot world: 3 ; inline enum READ = 01, WRITE = 02 } ; inline int File::isRead() return mode & READ ; } inline int File::isWrite() return mode & WRITE ; } & C++ bitset 2.5 virtual virtual virtual

23 static : virtual void swap index(int i, int j) const= 0; class test public: virtual int a(int &i)=0;... test exam; //Error new delete operand 2.

24 18 CHAPTER 2. CLASS 3. ** 4. = [] () -> 2.7 outward conversion operator type(); : operator double(); static cast<double>(obj) double(obj) obj.operator double() 2.8 operator= 3 1. public

25 2.9. VIRTUAL INHERITANCE private 3. protected protected private private protected 2.9 virtual inheritance C++ vitual base class : class Derived : public virtual Base... // public virtual

26 20 CHAPTER 2. CLASS RTTI run-time type identification RTTI C++ RTTI

27 2.10. RTTI RUN-TIME TYPE IDENTIFICATION dynamic cast 2. typeid dynamic cast dynamic cast downcasting C++ dynamic cast dynamic cast dynamic cast 0 dynamic cast dynamic cast dynamic cast void somefunc( Base *obj ) if( Derived *dobj = dynamic cast< Derived* >( obj ) ) // do something with derived function } else // do something with base function } } void somefunc2( Base &obj ) try Derived &dobj = dynamic cast< Derived& >( obj ) ) // do something with derived function } catch( std::bad cast ) // do something with base function } dynamic cast bad cast <typeinfo> typeid typeid typeid

28 22 CHAPTER 2. CLASS typeid <typeinfo> typeid(type) typeid(object) typeid(expression) type info cout<<typeid(obj).name()<<endl; int n ; cout<<typeid( n ).name() ; // int cout<<typeid( 8.1 ).name() ; // double typeid typeid class Base /* */ class Derived : public Base /* */ Derived dobj ; Base *pb = &dobj ; cout<<typeid( *pb ).name()<<endl ; // Base typeid Base Derived typeid( pb ).name() Base* typeid type info type info type info class type info private: type info( const type info& ) ; type info& operator= (const type info& ) ; public: virtual type info() ; int operator== ( const type info& ) const ; int operator!= ( const type info& ) const ; const char * name() const ; type info type info typeid

29 Chapter 3 template 3.1 float (*fn)(float, int) = &power; float result=power<float, int>(a, n); 3.2 empty size() 0 empty list size 23

30 24 CHAPTER 3. TEMPLATE

31 Chapter 4 Standard Template Library (STL) 4.1 functional function objects C++ operator() struct myclass int operator() (int a) return a; } } myobject ; int x = myobject(0) ; // myobject <functional> unary function template<class Arg, class Result> struct unary function typedef Arg argument type ; typedef Result result type ; } ; operator() operator() 25

32 26 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) binary function template<class Arg1, class Arg2, class Result> struct binary function typedef Arg1 first argument type ; typedef Arg2 second argument type ; typedef Result result type ; } ; operator() operator() Operator classes Arithmetic operations plus template <class T> struct plus : binary function <T,T,T> T operator() (const T& x, const T& y) const return x+y ; } // plus example #include <iostream> #include <functional> #include <algorithm> using namespace std; int main () int first[]=1,2,3,4,5 int second[]=10,20,30,40,50 int results[5]; transform ( first, first+5, second, results, plus<int>() ); for (int i=0; i<5; i++) cout << results[i] << ; cout << endl; return 0; }

33 4.1. FUNCTIONAL 27 minus template <class T> struct minus : binary function <T,T,T> T operator() (const T& x, const T& y) const return x-y ; } multiplies template <class T> struct multiplies : binary function <T,T,T> T operator() (const T& x, const T& y) const return x*y ; } divides template <class T> struct divides : binary function <T,T,T> T operator() (const T& x, const T& y) const return x/y ; } modulus template <class T> struct plus : binary function <T,T,T> T operator() (const T& x, const T& y) const return x%y ; } negate template <class T> struct negate : unary function <T,T> T operator() (const T& x) const return -x ; }

34 28 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) // negate example int main () int numbers[]=10,-20,30,-40,50 transform ( numbers, numbers+5, numbers, negate<int>() ); for (int i=0; i<5; i++) cout << numbers[i] << ; return 0; } Comparison operations equal to template <class T> struct equal to : binary function <T,T,bool> T operator() (const T& x, const T& y) const return x==y ; } int main () pair<int*,int*> ptiter; int foo[]=10,20,30,40,50 int bar[]=10,20,40,80,160 ptiter=mismatch ( foo, foo+5, bar, equal to<int>() ); cout << First mistmatching pair is: << *ptiter.first; cout << and << *ptiter.second << endl; return 0; } First mismatching pair is: 30 and 40 no equal to greater less greater equal less equal Logical operations logical and template <class T> struct logical and : binary function <T,T,bool> T operator() (const T& x, const T& y) const return x&&y ; }

35 4.1. FUNCTIONAL 29 logical or logical not Adaptor and conversion functions Negators not1 negation template <class Predicate> unary negate<predicate> not1 (const Predicate& pred) return unary negate<predicate>(pred); unary negate template <class Predicate> class unary negate : public unary function <typename Predicate::argument type,bool> protected: Predicate fn; public: explicit unary negate ( const Predicate& pred ) : fn (pred) } bool operator() (const typename Predicate::argument type& x) const return!fn(x); } struct IsOdd : unary function<int,bool> bool operator() (const int& x) const return x%2==1; } int main () int values[] = 1,2,3,4,5 int cx; cx = count if ( values, values+5, not1(isodd()) ); cout << There are << cx << elements with even values.\n ; return 0; } There are 2 elements with even values. not2 negation

36 30 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) template <class Predicate> binary negate<predicate> not2 (const Predicate& pred) return binary negate<predicate>(pred); Parameter binders bind1st template <class Operation, class T> binder1st<operation> bind1st (const Operation& op, const T& x) return binder1st<operation>(op, typename Operation::first argument type(x)); } binder1st template <class Operation> class binder1st : public unary function <typename Operation::second argument type, typename Operation::result type> protected: Operation op; typename Operation::first argument type value; public: binder1st (const Operation& x, const typename Operation::first argument type& y) : op (x), value(y) } typename Operation::result type operator() (const typename Operation::second argument type& x) const return op(value,x); } int numbers[] = 10,20,30,40,50,10 int cx; cx = count if (numbers, numbers+6, bind1st(equal to<int>(),10) ); cout << There are << cx << elements that are equal to 10.\n ; There are 2 elements that are equal to 10. bind2nd

37 4.1. FUNCTIONAL 31 Conversors template <class Operation, class T> binder2nd<operation> bind2nd (const Operation& op, const T& x) return binder2nd<operation>(op, typename Operation::second argument type(x)); } ptr fun mem fun mem fun ref Instrumental types unary negate: Generate negation of unary function object class (class template) binary negate: Generate negation of binary function object class (class template) binder1st: Generate function object class with 1st parameter binded (class template) binder2nd: Generate function object class with 2nd parameter binded (class template) pointer to unary function: Generate unary function object class from pointer (class template) pointer to binary function: Generate binary function object class from pointer (class template) mem fun t: Generate function object class from parameterless member (pointer version) (class template) mem fun1 t: Generate function object class from single-parameter member (pointer version) (class template) const mem fun t: Generate function object class from const parameterless member (pointer version) (class template) const mem fun1 t: Generate function object class from single-parameter const member (pointer version) (class template) mem fun ref t: Generate function object class from parameterless member (reference version) (class template)

38 32 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) mem fun1 ref t: Generate function object class from single-parameter member (reference version) (class template) const mem fun ref t: Generate function object class from const parameterless member (reference version) (class template) const mem fun1 ref t: Generate function object class from single-parameter const member (reference version) (class template)

39 count() template <class InputIterator, class T> typename iterator traits<inputiterator>::difference type count ( InputIterator first, InputIterator last, const T& value ); [first,last) value (iterator traits<inputiterator>::difference type), ptrdiff t count if() template <class InputIterator, class T> typename iterator traits<inputiterator>::difference type count if ( InputIterator first, InputIterator last, Predicate pred ); [first,last) pred STL count if() operator() STL operator() STL operator() true false

40 34 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) const string ToothbrushCode( 0003 ); class IsAToothbrush public: bool operator() ( string& SalesRecord ) return SalesRecord.substr(0,4)==ToothbrushCode; } int main (void) list<string> SalesRecords; SalesRecords.push back( 0001 Soap ); SalesRecords.push back( 0002 Shampoo ); SalesRecords.push back( 0003 Toothbrush ); SalesRecords.push back( 0004 Toothpaste ); SalesRecords.push back( 0003 Toothbrush ); } int NumberOfToothbrushes(0); count if (SalesRecords.begin(), SalesRecords.end(), IsAToothbrush(), NumberOfToothbrushes); cout << There were << NumberOfToothbrushes << toothbrushes sold << endl; insert push back front back copy in copy out STL 4.4 vector<bool>? STL vector<bool> 1. STL

41 ITERATOR CONST ITERATOR REVERSE ITERATOR CONST REVER 2. bool STL C c T c operator[] vector<t> v ; T *p = &c[0]; // operator[] T* T bool vector<bool> bool bool vector bool 8 8 bool vector<bool> bitfield bool bool bool bool bool vector<bool> deque<bool>: deque vector reserve capacity deque<bool> STL bool deque deque<bool> bool C API bitset: bitset STL C++ STL STL iterator vector<bool> vector<bool> flip collection of bits bitset iterator const iterator reverse iterator const reverse iterator vector<t> insert erase iterator insert(iterator position, const T& x); iterator erase(iterator position); iterator erase(iterator rangebegin, iterator rangeend); iterator const iterator reverse iterator const reverse iterator const iterator iterator const reverse iterator reverse iterator

42 36 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) Figure 4.1:. iterator const reverse insert erase iterator iterator const reverse const iterator iterator reverse iterator iterator 28 iterator const iterator distance advance const iterator iterator const iterator iterator vector string const iterator iterator typedef deque<int> IntDeque ; typedef IntDeque::iterator Iter ; typedef IntDeque::const iterator ConstIter ; IntDeque d ; ConstIter ci ;... // ci d Iter i(d.begin()) ; // i d advance(i, distance<constiter>(i, ci)) ; // i ci // i ci const iterator const iterator iterator iterator const iterator iterator vector string deque

43 REVERSE ITERATOR BASE() ITERATOR reverse iterator base() iterator reverse iterator base() iterator vector<int> v; v.reserve(5); // 14 for(int i = 0 i 5; ++ i) // vector 1 5 v.push back(i); } vector<int>::reverse iterator ri = find(v.rbegin(), v.rend(), 3); // ri 3 vector<int>::iterator i(ri.base()); // i ri base vector Figure 4.2:. reverse iterator base() iterator rbegin() rend() begin() end() 1. reverse iterator ri ri.base() ri ri.base() ri.base() ri iterator 2. reverse iterator ri ri.base() ri ri.base() ri.base()

44 38 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) ri iterator v.erase((++ri).base()) ; // ri ri remove erase remove STL remove template<class ForwardIterator, class T> ForwardIterator remove(forwarditerator first, ForwardIterator last, const T& value); remove remove remove remove remove remove remove vector<int> v Figure 4.3: remove v. remove vector<int>::iterator newend( remove( v.begin(), v.end(), 99 ) ) ; v Figure 4.4: remove v. c++ STL remove v

45 REMOVE 39 Figure 4.5: STL remove v. v.erase( remove(v.begin(), v.end(), 99), v.end() ) ; list remove remove erase STL remove remove remove remove if unique unique list remove list::unique remove Widget Widget class Widget public:... bool iscertified() const ;... verctor<widget*> v ;... v.push back(new Widget) ;... v Widget erase-remove v.erase( remove if(v.begin(), v.end(), not1(mem fun(&widget::iscertified))), v.end() ) ; remove if v Widget remove if v

46 40 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL) Figure 4.6: remove if v. Figure 4.7: remove if v. remove remove if unique partition remove erase-remove Widget void delandnullifyuncertified(widget*& pwidget) // *pwidget // Widget if (!pwidget->iscertified()) // delete pwidget; pwidget = 0; } } for each(v.begin(), v.end(), // Widget delandnullifyuncertified); // v.erase(remove(v.begin(), v.end(), // v static cast<widget*>(0)), // 0 v.end()); // C++ remove

47 REMOVE 41 remove template<typename T> // RCSP = Reference Counting Smart Pointer class RCSP... typedef RCSP< Widget > RCSPW; // RCSPW = RCSP to Widget vector< RCSPW > v; // vector Widget... v.push back(rcspw(new Widget));... v.erase(remove if(v.begin(), v.end(), // Widget not1(mem fun(&widget::iscertified))), // v.end()); RCSP<Widget> Widget* Widget::isCertified Boost shared ptr

48 42 CHAPTER 4. STANDARD TEMPLATE LIBRARY (STL)

49 Bibliography [1] Stanley B. Lippman and Josée Lajoie C++ Primer 2002 [2] Scott Meyers Effective STL