Question

if I have for example some class Base and derived from it Derived
Also I have some list of shared pointers:

list<shared_ptr<Base> > list

I create shared pointer:

line 5    shared_ptr<Derived> ptr(new Derived(//some constructor));

my question is, can I do something like this:

list.push_back(ptr);

if Yes, can somebody explain why can I recieve an error (I receive this on the line 5)

no matching function for call to //here It writes me my constructor to Derived

thanks in advance for any help

Answer 1

my question is, can I do something like this: list.push_back(ptr);

Yes – your problem has nothing to do with inheritance or smart pointers – you simply don’t have the constructor declared you are trying to use.

A simple example that reproduces the error is:

struct X {};
X x(1);

Which gives you:

no matching function for call to ‘X::X(int)‘

You fix that by either constructing the instance differently or by adding the missing constructor:

struct X { X(int) {} };