CODEWITHSUNDEEP
c++standard-library
Robinson
Robinson

Reputation: 10122

Is there a std::noncopyable (or equivalent)?

There's a boost::noncopyable and I have my own noncopyable class in my library. Is there a std::noncopyable or equivalent knocking around in the latest C++ standard?

It's a small thing but deriving from such a class makes the intention much clearer.

Upvotes: 34

Views: 29979

Answers (2)

CashCow
CashCow

Reputation: 31445

No, because there is a standard way to make a class non-copyable:

class MyClass
{
   MyClass(const MyClass&) = delete;
   MyClass& operator=(const MyClass&) = delete;
}:

A class that is non-copyable can however be made movable by overloading a constructor from MyClass&&.

The declaration to make the class non-copyable (above) can be in the public or private section.

If you don't really want to type all that out every time, you can always define a macro something like:

#define NONCOPYABLE(Type) Type(const Type&)=delete; Type& operator=(const Type&)=delete

class MyClass
{
    NONCOPYABLE(MyClass);

    // etc.
};

Upvotes: 26

user2015735
user2015735

Reputation: 419

I'm sure you already figured it out by reading CashCow's post, but I thought I might as well provide a base class for noncopyable classes.

class Noncopyable {
public:
    Noncopyable() = default;
    ~Noncopyable() = default;

private:
    Noncopyable(const Noncopyable&) = delete;
    Noncopyable& operator=(const Noncopyable&) = delete;
};

Upvotes: 25

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