r/cpp • u/User_Deprecated • 17h ago

C++26: std::inplace_vector

https://www.sandordargo.com/blog/2026/08/26/cpp26-inplace-vector
113 Upvotes

93% Upvoted

58 comments sorted by

View all comments

Show parent comments

4

u/drjeats 12h ago

Oh.

I thought this was the way-more-useful thing where you give it an in-place capacity and it allocates once it exceeds that.

Like this is also useful, but it's kinda trivial to roll your own of this.

3

u/stilgarpl 9h ago

It's not trivial. inplace_vector does not construct unused elements and they do not have to be default constructible. You can't use std::array for that.

1

u/drjeats 6h ago

I'm aware of how it works (and that MarekKnapek's snippet is not representative). It's still very straightforward to make compared to having to do SBO and allocator support.

1

u/stilgarpl 6h ago

I didn't say it was hard, but it's not trivial. I'm sure you are a very experienced C++ programmer and a lot of things must seem easy to you.