copy constructor

[gungurthisrilatha]

Am writing a program using copy constructor the code goes like this

class test
{
int a,b;
public:
test()
{
//statements
}
test(test &t) //copy constructor
{
a=t.a;
b=t.b;
cout<<a<<b;
}

};
void main()
{
test t;
test t1;
t1=t; //invoke copy constructor
}
it has to assign the vals of t obj to t1 but when am compiling it is not invoking the copy constructor can u people help me out.

[rpgfan3233]

The copy constructor is only invoked when the object is actually constructed. Try this:
test t1 = t;

That should work. If you use t1=t alone, then you would need to overload the assignment operator, which is a different task in itself.

[jsmith]

Also, you don't even need to implement the copy constructor as newer compilers will autogenerate one for you that does a member-wise copy (older ones did a bit-wise copy which in your case would also work since your class contains only POD types [Plain-Old-Data]).

However, compilers do not autogenerate assignment operators, so you'd need to write
it:

class test {
   // ... your stuff here
  
   test& operator=( test const& rhs ) {
        a = rhs.a; 
        b = rhs.b;
        return *this;
   }
};