Copy constructor with non const rhs arg

Eljay Love-Jensen eljay@adobe.com
Wed May 12 16:26:00 GMT 2004


hi Paul,

Hmm, I guess pass-by-value a Copy Constructor doth not make.

Solution #1
--------------------------------
#include <memory>

using namespace std;

class Foo
{
public:
     Foo(Foo const& in);
private:
     auto_ptr<int> m;
};

Foo::Foo(Foo const& in)
: m(const_cast<Foo&>(in).m)
{
}

Foo FooFactory();
int main()
{
     Foo f(FooFactory());
     Foo f2 = FooFactory();
}
--------------------------------

Solution #2
--------------------------------
#include <memory>

using namespace std;

class Foo
{
public:
     Foo(Foo const& in);
private:
     mutable auto_ptr<int> m;
};

Foo::Foo(Foo const& in)
: m(in.m)
{
}

Foo FooFactory();
int main()
{
     Foo f(FooFactory());
     Foo f2 = FooFactory();
}
--------------------------------

HTH.
--Eljay



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