seanbax

5 ms·

1.
by seanbax 1y ago
Lifetime parameters are necessary for borrow checking. And you need a special operator for initiating a borrow. You need immutability by default, because mutability everywhere violates exclusivity.
2.
by seanbax 1y ago
Which ideas aren't strictly necessary to achieve safety in C++?
3.
by seanbax 1y ago
template<typename _RandomAccessIterator> _GLIBCXX20_CONSTEXPR inline void sort(_RandomAccessIterator __first, _RandomAccessIterator __last) { // concept requirements __glibcxx_function_requir
4.
by seanbax 1y ago
Python doesn't have lvalues in the way that C++ and Rust do. You can't refcount everything and still pass lvalues to subobjects. If lvalues to subobjects are important, you need borrow checking.
5.
by seanbax 1y ago
I illustrate why it won't work with a number of examples here: https://www.circle-lang.org/draft-profiles.html To address your points: 1. The safe subset of C++ is too small to do anything with. 2. The Standard Library
6.
by seanbax 1y ago
The Profiles authors are the ones claiming this uses local analysis only: https://news.ycombinator.com/item?id=41942126 They are clear that Profiles infers everything from function types and not function bodies. Obviously t
7.
by seanbax 1y ago
I would have implemented profiles if profiles had a chance of working. But they will not ever work. I present many examples of why they fail here: https://www.circle-lang.org/draft-profiles.html People who say Profiles are
8.
by seanbax 2y ago
You do solely rely on the declaration. From P3465: "why this is a scalable compile-time solution, because it requires only function-local analysis" Profiles uses local analysis, as does borrow checking. Whole program analysis is s
9.
by seanbax 2y ago
If the vector has to be resized in push_back, the implementation copy-constructs a new object from x. It resizes the buffer. Then it move-constructs the copy into the buffer. The cost is only a move construct per resize... So it's on t
10.
by seanbax 2y ago
From P3465: "why this is a scalable compile-time solution, because it requires only function-local analysis" From P1179: "This paper ... shows how to efficiently diagnose many common cases of dangling (use-after-free) in C++
11.
by seanbax 2y ago
Presenting a familiar syntax certainly makes it easier to follow.
12.
by seanbax 4y ago
https://itanium-cxx-abi.github.io/cxx-abi/abi.html See all the stuff there? exceptions, vtable layout, rtti, mangling, etc. There's a Windows equivalent for all of that. That's what I want access to.
13.
by seanbax 4y ago
Yes, interfaces open that up, and to a lesser extent choice types open that up. If your choice type supports all the alternatives from the original overload set, then you can reduce to one function.
14.
by seanbax 4y ago
That's right. I'm fine with normal C++ syntax. But other people have other opinions. And there is an allure of getting to a CFG so that non-compiler tooling could build a parse tree and do useful transformations. That's a goo
15.
by seanbax 4y ago
I'd like to target Windows. Windows does impose a specific C++ ABI, but it's completely undocumented. It's really just whatever Visual C++ does. C++ ABI is very complex, especially vtable layout and RTTI and EH. I am looking
16.
by seanbax 5y ago
My favorite use is putting user-defined attributes on data members, and using reflection to generate a UI to manipulate those values. I do it with these shadertoys: https://github.com/seanbaxter/shaders#reflection-and-a
17.
by seanbax 5y ago
Enum to string is a one-line expression in Circle: https://godbolt.org/z/93f5o77zv Circle has dozens of special traits for accessing useful stuff about types, packs, etc. Don't need to overengineer such a simple t