Why Was `std::make_unique` Missing from C 11, and How Does Perfect Forwarding Enhance Its Functionality?

make_unique and Perfect Forwarding

Why no std::make_unique in C 11?

Despite the advantages of reducing verbosity and aiding in type safety, std::make_unique was not included in the C 11 standard. Herb Sutter, chair of the C standardization committee, attributes this omission to an oversight.

std::forward and Perfect Forwarding Explained

In the user-defined make_unique implementation, std::forward(args)... is used to perfectly forward the arguments to the constructor of T. This technique ensures that the arguments are passed as the most optimal rvalue (or lvalue) references.

When std::forward is applied to an lvalue reference, it converts it to an rvalue reference, allowing the constructor to bind to an rvalue directly. Conversely, if std::forward is applied to an rvalue reference, it does nothing.

Implementation Details

The make_unique implementation creates a new instance of T by allocating memory with new T and then invoking its constructor with the forwarded arguments. The use of perfect forwarding prevents unnecessary copies or unnecessary temporary objects.

Conclusion

Although not part of C 11, std::make_unique has become a widely adopted convention for concisely creating unique pointers. It enhances code readability, simplifies type handling, and ensures efficient resource management. Its anticipated inclusion in C 14 further underscores its importance in modern C programming.

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