Yes. duck takes ownership of the vector by moving it into its internal storage.
As a bonus, if you tried passing in an lvalue, it will reject the input unless you add the "copyable" trait, so it ends up mitigating some hidden copies.
I see there's an issue in the tracker to get more accurate data, and since it's using an under dev feature in compilers, it's not going to be definitive, but any rough numbers?
I don't have any numbers, but it is pretty slow. You can try making some edits in Compiler Explorer to see for yourself (though that of course has some impact from network requests).
One reason is that, like you said, the feature is still new. Additionally I made pretty liberal use of the std::ranges library in my implementation which has notoriously bad compile times. That could be an area to improve upon.
Another may be a bit more structural. If you want to call myObj.foo() via reflection, you have to linearly search members_of(myObj) for the one named "foo", and then call that. Actual compilers I assume use some kind of hash table.
The hand-waving solution is "put it in a PCH", but I am hoping to put some more effort into optimizing build time here in the future.
This library tries its best to mitigate that, catching common errors and whatnot, but it can definitely still happen. C++ doesn't have full token injection yet, so it avoids some of the more common pitfalls, if incidentally.
As an aside, you may want to check out Jai's approach. I believe everything you generate statically gets turned into a file by the compiler for debugging purposes, which it provides references to in the output.
I don’t really like much about C++ anymore, but I still enjoy reading C++ articles and listening to C++ podcasts, and I would consider it beautiful. Oftentimes the things I dislike about it are also the beautiful things. The term “beautiful mess” seems appropriate.
It’s a bit like a well-kept Victorian home. The amount of work, money, and dealing with discomfort that goes into maintaining one isn’t something I really want to experience for myself. But the amount of skill and craftsmanship that it takes to preserve one is still impressive, and I have to appreciate the respect for history and the care that goes into balancing it with modern concerns.
And talking to people who do live the life is always a great learning experience.
Check out the source code: https://github.com/RyanJK5/rjk-duck
```
10: rjk::duck<Container> c{std::vector<int>{1, 2, 3}};
11: c.size(); // 3
12:
13: c = std::string{"hello"};
```
Does the assignment on line 13 call the destrucor for the vector of ints created on line 10? Does the vector get leaked? What's going on here?
As a bonus, if you tried passing in an lvalue, it will reject the input unless you add the "copyable" trait, so it ends up mitigating some hidden copies.
I see there's an issue in the tracker to get more accurate data, and since it's using an under dev feature in compilers, it's not going to be definitive, but any rough numbers?
One reason is that, like you said, the feature is still new. Additionally I made pretty liberal use of the std::ranges library in my implementation which has notoriously bad compile times. That could be an area to improve upon.
Another may be a bit more structural. If you want to call myObj.foo() via reflection, you have to linearly search members_of(myObj) for the one named "foo", and then call that. Actual compilers I assume use some kind of hash table.
The hand-waving solution is "put it in a PCH", but I am hoping to put some more effort into optimizing build time here in the future.
As an aside, you may want to check out Jai's approach. I believe everything you generate statically gets turned into a file by the compiler for debugging purposes, which it provides references to in the output.
Those against IDEs, well they already voted against good tooling in first place.
...but, as they say, beauty is in the eye of the beholder!
It’s a bit like a well-kept Victorian home. The amount of work, money, and dealing with discomfort that goes into maintaining one isn’t something I really want to experience for myself. But the amount of skill and craftsmanship that it takes to preserve one is still impressive, and I have to appreciate the respect for history and the care that goes into balancing it with modern concerns.
And talking to people who do live the life is always a great learning experience.
I had the same misunderstanding before I get to know CS. that was 30 years ago.
I'm also glad I do not write C++ on the daily anymore: luckily my software does not need that kind of performance characteristics.
Either directly on top of a runtime/compiler written in C++, or as indirect dependency on a C++ compiler toolchain.
You can write pretty fast and reasonable code nowadays.