When i develop a destructor, do i require to explicitly call, C/C++ Programming

When I develop a destructor, do I require to explicitly call the destructors for my member objects?

 

 

Posted Date: 3/15/2013 5:55:11 AM | Location : United States





Let''s work an instance. Imagine you need your constructor Foo::Foo(char) to call another constructor of the similar class, namely Foo::Foo(char,int), in order that Foo::Foo(char,int) would help initialize this object. Unluckily there''s no way to do this in C++.

Some of people do it anyway. Unluckily it doesn''t do what they want. For instance, the line Foo(x, 0); does not call Foo::Foo(char,int) on the this object. Rather then it calls Foo::Foo(char,int) to initialize temporary, local object (not this), then it instantly destructs that temporary while control flows over the ;.

class Foo { public: Foo(char x);

Foo(char x, int y);

...

};

 

Foo::Foo(char x)

{

...

Foo(x, 0); // this line does NOT help initialize the this object!!

...

}

You can combine sometimes two constructors through a default parameter:

class Foo {

public:

Foo(char x, int y=0); // this line combines the two constructors

...

};

If that doesn''t work, for example if there isn''t an suitable default parameter which combines the two constructors, every so often you can share their common code in a private init() member function:

class Foo { public: Foo(char x);

Foo(char x, int y);

... private:

void init(char x, int y);

};

 

Foo::Foo(char x)

{

init(x, int(x) + 7);

...

}

Foo::Foo(char x, int y)

{

init(x, y);

...

}

void Foo::init(char x, int y)

{

...

}

BTW do NOT attempt to get this via placement new. Some of the people think they can say new(this) Foo(x, int(x)+7) in the body of Foo::Foo(char). Constructors do a bunch of little magical things behind the scenes, but that bad technique steps on those partly constructed bits.

 

Posted by | Posted Date: 3/15/2013 5:55:55 AM


Related Discussions:- When i develop a destructor, do i require to explicitly call, Assignment Help, Ask Question on When i develop a destructor, do i require to explicitly call, Get Answer, Expert's Help, When i develop a destructor, do i require to explicitly call Discussions

Write discussion on When i develop a destructor, do i require to explicitly call
Your posts are moderated
Related Questions
Use of random function: int main(void) {    int i,j;         for(j=0;j       {      // randomize();       for(i=0;i                  printf("%d\n", ran

Aim: To implement a program to convert time in 24 hour format to 12 hour format. Code:                       #include #include #include class time24 {


Use 16 digit credit card numbers that contain 15 digits an 1 check digit. The format of the card number consists of the 15 digits followed by the check digit. The check digit is co

6999066263304447777077766622337778 -----> message sent by the first smuggler. my name is robert---------> message decoded by the second smuggler. Where ‘0’ denotes the "space". Ex

write short notes about void pointers

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

what is c++ ?

Different implementations of OOP Object-oriented programming is not mainly concerned with the details of the program operation. Instead, it deals with the overall design of the