virtual

1、overload 在Pascal语法规则中，同一个UNIT里是不能存在两个同名的函数的，例如： function func(): Boolean; function func(const x: Char): Boolean; 这样是会出语法错误的，原因是因为标识符规则限制。但是问题出来了，如果我们需要几个功能相似但是参数不同的函数，那么根据标识符规则，我们就必须定义几个不同名，但是功能相同或相似的函数。 如，假设我需要一个函数，要实现返回参数一减去参数二后的值，那么我们就将这样定义函数： function SubInt(const Value1, Value2: Integer): Integer; functino SubReal(const Value1, Value2: Real): Real; function SubDouble(const Value1, Value2: Double): Double; implementation function SubInt(const Value1, Value2: Integer): Integer; begin Result:= Value1 - Value2; end; functino SubReal(const Value1, Value2: Real): Real; begin Result:= Value1 -

I'm developing android with SDK 2.3.3 using Eclipse IDE. As you all know to run my app, I should generate virtual device. From 'create new AVD' window, I can see many targets. There are 2 targets for API level 10 such as 'android 2.3.3' and Google APIs(Google Inc). Among those targets, I'm uncertain which one I should choose. My question is what's the difference between them. Thanks in advance Dan Zack Marrapese The Google API includes Google Maps and other Google-specific libraries. The Android one only includes core Android libraries. As for which one to choose, I would go with the Android

Can someone please explain about the size of the classes in the case of virtual inheritance involving virtual functions. class A{ char k[ 3 ]; public: virtual void a(){}; }; class B : public A{ char j[ 3 ]; public: virtual void b(){}; }; class C : public virtual A{ char i[ 3 ]; public: virtual void c(){}; }; class D : public B, public C{ char h[ 3 ]; public: virtual void d(){}; }; The output of the size of the classes is : sizeof(A): 8 sizeof(B): 12 sizeof(C): 16 sizeof(D): 32 The compiler I am using is gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3) sizeof(A): 8 3 bytes in the array, 1 byte

This question already has an answer here: Polymorphism & Pointers to arrays [duplicate] 3 answers class Base1 { private: int testInput; public: Base1(); virtual int GetRow(void) = 0; }; Base1::Base1() { testInput = 0; } class table : public Base1 { private: int row; public: table(); virtual int GetRow(void); }; table::table() { //Contructor row = 5; } int table::GetRow() { return row; } int main () { Base1* pBase = new table[3]; pBase[0].GetRow(); pBase[1].GetRow(); //when i get to this line, the compiler keep saying access // violation. pBase[2].GetRow(); return 0; } I'm trying to create an

文章目录 Learning Objectives Prior Knowledge Check Key Terms video Virtualization what is network virtualization ? examples of virtual machine technology motivation for network virtualization the promise of network virtualization 区分VPN和Virtual networks design goals build virtual nodes ，links or machines summary Applications of Virtual Networking three broad applications of virtual networking NFV 概念补充 **Overlay** **NFV** VINI和Emulab FLowVisor emulation和simulation Learning Objectives Discover what network virtualization is and why it is used Identify various ways of implementing virtual networks

I want to call the base class implementation of a virtual function using a member function pointer. class Base { public: virtual void func() { cout << "base" << endl; } }; class Derived: public Base { public: void func() { cout << "derived" << endl; } void callFunc() { void (Base::*fp)() = &Base::func; (this->*fp)(); // Derived::func will be called. // In my application I store the pointer for later use, // so I can't simply do Base::func(). } }; In the code above the derived class implementation of func will be called from callFunc. Is there a way I can save a member function pointer that