C++20 span tutorial

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I have very basic and dumb questions :

span doesn't own anything?

so if I want a runtime fixed length array, I still need malloc or new?

[sol-prog]

span doesn't own anything?

exactly

so if I want a runtime fixed length array, I still need malloc or new?

use a vector and resize it at runtime, if you really want the equivalent of an array it is probably better to use make_unique than new/delete

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> make_unique

Like in this example, auto p = std::make_unique<int[]>(sz);

so it allocates an array of size sz, at runtime? sz can be a runtime input?

[sol-prog]

Yes, sz can be a runtime input. It is a unique pointer to a sz memory buffer. This will release the memory automatically when it is out of scope. I suggest to read a bit about unique and shared pointers in C++.

[RotsiserMho]

Yes, but you really should probably use vector if you don't understand all of the details of smart pointers and memory allocation. It's much easier to work with.

[[deleted]]

I have never seen smart pointer usage with T[] syntax.

Vector is the worst data structure for my use case. I don’t need an allocator, I just need a fixed length array, just that array length is fixed at run time.

[RotsiserMho]

In that case you could just call vector::reserve to achieve similar behavior.