| Topic: |
DEVELOP > c-Plus-Plus |
| User: |
"" |
| Date: |
19 Jan 2008 11:09:40 PM |
| Object: |
Templates, overloading & const |
Hi,
I have the following code.
struct Object
{
int m_id;
void setId(int const id)
{
m_id = id;
}
};
// version 1
template < class T >
void resetId(T &obj, int const id)
{
obj.setId(id);
}
// version 2
template < class T >
void resetId(boost::shared_ptr < T > const &obj, int const id)
{
obj->setId(id);
}
int main()
{
Object obj1;
resetId(obj1, 1); // calls version 1
boost::shared_ptr < Object > obj2;
resetId(obj2, 2); // This calls version 1 too
}
This is with GCC 3.2.3...
How can I make sure that the call "resetId(obj2, 2)" calls version 2
that is overloaded for shared_ptr objects.
.
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| User: "Salt_Peter" |
|
| Title: Re: Templates, overloading & const |
20 Jan 2008 02:06:42 AM |
|
|
On Jan 20, 12:09 am, wrote:
Hi,
I have the following code.
struct Object
{
int m_id;
void setId(int const id)
{
m_id = id;
}
};
// version 1
template < class T >
void resetId(T &obj, int const id)
{
obj.setId(id);
}
// version 2
template < class T >
void resetId(boost::shared_ptr < T > const &obj, int const id)
void resetId(boost::shared_ptr< T >& sp, int const id)
{
obj->setId(id);
sp->setId(id);
}
int main()
{
Object obj1;
resetId(obj1, 1); // calls version 1
boost::shared_ptr < Object > obj2;
resetId(obj2, 2); // This calls version 1 too
boost::shared_ptr< Object > bsp(new Object);
resetId(bsp, 2);
note: don't construct a temporary, see boost's notes on shared_ptr
}
This is with GCC 3.2.3...
How can I make sure that the call "resetId(obj2, 2)" calls version 2
that is overloaded for shared_ptr objects.
Any reason you aren't using constructors? After all, the compiler will
generate a default ctor if you don't. And you can supply as many
constructors as you need. Do not ignore ctors in C++, including copy
constructors. In fact, i find its *very* rare that i don't provide
ctors + init list for types. They save a lot of hardship and greatly
enhance the code.
struct Object
{
Object() : m_id(0) { } // default ctor
Object(const int id) : m_id(id) { } // parametized ctor
resetId(int const id) { m_id = id; }
private:
int m_id;
};
int main()
{
Object obj(1);
}
.
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| User: "" |
|
| Title: Re: Templates, overloading & const |
30 Jan 2008 06:30:13 PM |
|
|
The code is just an example piece from the actual problem. I don't
have the luxury of constructors that take just the ID, because the
code for class Object is generated from a kind of IDL where there is
no constructor that just sets the ID value and ID is a member that I
dont define, but generated by the IDL compiler automatically. Hope
that helps.
.
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