Construction of member objects

[Joost Ronkes Agerbeek]

Are member objects constructed before the body of the constructor executes?

Consider the following example. Is this okay or is it possible that _bar
will be created after the call to DoBar()?

class Bar
{
public:
Set(int i) { _i = i; }

private:
int _i;
};

class Foo
{
public:
Foo() { DoBar(); }

private:
void DoBar() { _bar.Set(10); }
Bar _bar;
};

Thanks in advance,
Joost

 

[llewelly]

Are member objects constructed before the body of the constructor
executes?
Yes.


Consider the following example. Is this okay or is it possible that _bar
will be created after the call to DoBar()?
No.


class Bar
{
public:
Set(int i) { _i = i; }

private:
int _i;
};

class Foo
{
public:
Foo() { DoBar(); }

private:
void DoBar() { _bar.Set(10); }
Bar _bar;
};

[snip]

 

[Howard]

No.

Umm that was an either/or question. I think he means "no: _bar will not
be created after the call to DoBar(), but will be already be created by that
time". In other words, yes, it's ok.

class Bar
{
public:
Set(int i) { _i = i; }

private:
int _i;
};

class Foo
{
public:
Foo() { DoBar(); }

private:
void DoBar() { _bar.Set(10); }
Bar _bar;
};

[snip]

 

[Victor Bazarov]

No.

Umm that was an either/or question. I think he means "no: _bar will not
be created after the call to DoBar(), but will be already be created by that
time". In other words, yes, it's ok.

class Bar
{
public:
Set(int i) { _i = i; }

private:
int _i;
};

class Foo
{
public:
Foo() { DoBar(); }

private:
void DoBar() { _bar.Set(10); }
Bar _bar;
};

[snip]

The statement is ambiguous: _bar is created as soon as Foo is created and
before the body of Foo() is entered. By the time DoBar() is called, _bar
has already been created (with its member _i uninitialised). So, calling
"DoBar", which in turn calls Bar::Set, is OK.

Victor

 

[JKop]

int _i;

Let me please just take this opportunity to express my disgust at your
coding style.


-JKop

 

[Joost Ronkes Agerbeek]

Thanks everyone, for clearing that up.

 

[Joost Ronkes Agerbeek]

:-D Any suggestions for how I should clean up my act?

Joost

 

[Alan Johnson]

:-D Any suggestions for how I should clean up my act?

Joost

One solution that may be more to his liking, would be to change your
class as such:

class Bar
{
public:
Set(int i) { Bar::i = i; }

private:
int i;
};



Alan

 

[JKop]

Joost Ronkes Agerbeek posted:

:-D Any suggestions for how I should clean up my act?

Joost

Well, here's what *I* might do: Name the member variable:

m_Chocolate


And name the variable passed to a function:

Chocolate


And for global variables:

g_Chocolate


And for static member variables:

ClassName::s_Chocolate


And for a pointer:

pChocolate


-JKop

 

[Jeff Schwab]

Joost Ronkes Agerbeek posted:





Well, here's what *I* might do: Name the member variable:

m_Chocolate


And name the variable passed to a function:

Chocolate


And for global variables:

g_Chocolate


And for static member variables:

ClassName::s_Chocolate


And for a pointer:

pChocolate


-JKop

Let me please just take this opportunity to express my disgust at your
coding style.