CODEWITHSUNDEEP
c++c++11shared-ptr
Malvineous
Malvineous

Reputation: 27300

What's the easiest way to create an empty shared_ptr?

If you have a type that is quite long, in a shared_ptr, what's the easiest way to return the equivalent of a null pointer? In C++03 I was doing the following, but I'm wondering whether C++11 has introduced any better alternatives?

std::shared_ptr<
    std::vector<std::pair<int, std::map<std::string, std::string>>>
> getComplicatedType()
{
    // Do some checks, can't create type, so return an empty shared_ptr
    return std::shared_ptr<
        std::vector<std::pair<int, std::map<std::string, std::string>>>
    >();
}

I realise you could use typedef to create an alias for the type, but I'm looking for a nicer solution where the compiler can deduce the type automatically.

Upvotes: 5

Views: 8742

Answers (2)

David
David

Reputation: 28178

return nullptr;

Possibly a little more clear than return {};

Upvotes: 17

Brian Bi
Brian Bi

Reputation: 119069

return {};

This value-initializes the return type, which in the case of a smart pointer initializes it to null.

Upvotes: 7

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