CODEWITHSUNDEEP
c++stliteratorcontainers
ToBe
ToBe

Reputation: 971

How to use std::back_inserter to insert into a container (only have a pointer to container)

I would like to transform from foo to bar. 

struct A
{
    explicit A(int d): m_d(d) {};
private:
    int m_d;
};
A some_function (int i) { return A(2*i); }

std::vector<int> foo; 
std::vector<A> bar; // This is part of a Library not under my control

The interface only provides pbar

std::vector<A>* pbar =&bar; // This is the interface to the part of a Library not under my control

Is it legal to dereference pbar und use it as argument for back_inserter? Why?

std::transform (foo.begin(), foo.end(), std::back_inserter(*pbar), some_function);

A full example is here : http://coliru.stacked-crooked.com/a/2aec8d000cabf78b

Upvotes: 1

Views: 1636

Answers (1)

Jason R
Jason R

Reputation: 11696

Yes, there's no problem with doing that at all. I'm not really sure what the source of your confusion is, so I'm not sure how to answer "why." If you have a non-const pointer to an object, you're allowed to dereference it and pass it to functions that need a non-const reference (like std::back_inserter).

Upvotes: 2

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