shared_ptr vs unique_ptr with arrays [duplicate]

Question

This question already has an answer here:

Why isn't there a std::shared_ptr<T[]> specialisation? (1 answer)

Closed 8 years ago.

this does not work:

std::shared_ptr <char[]> ptr(new char[100]);
ptr[10] = '\0';

and this works:

std::unique_ptr <char[]> ptr(new char[100]);
ptr[10] = '\0';

I get compliler error C2676, meaning that "does not define this operator or a conversion to a type acceptable to the predefined operator". Any idea why is it so?

Answer 1

So some thoughts:

• std::shared_ptr<char[]> ptr(new char[100]); should be a syntax error all by itself.
• For whatever reason, unique_ptr was enabled to support the std::unique_ptr<char[]> syntax. Some of the rationale can be found here.
• The std::shared_ptr<T>::operator[] call also doesn't work, because std::shared_ptr does not implement it, only std::unique_ptr does.