Re:The Next Step for Generics
by munificent on Tuesday June 16, 2020 @06:03PM
(#23544837)
Instead of a spectrum, I think of it more qualitatively. Rust says that lifetime is a fundamental, necessary part of an API's design. To call an API, you have to think about the ownership of what you send to it and what you receive.
C also makes you think about ownership in your API design, it's just the language doesn't give you any real tools to express or enforce it. C++ gives you a bunch of tools and options, but you have to hope that you and the API you want to use agreed on which subset of the tools to use.
Garbage collected languages specifically take memory management out of the API design by declaring that the runtime will take care of it for everyone.
If you want lifetime to be something an API can control, then I think Rust's approach makes sense even though it obviously adds complexity. If you don't, then, yes, removing it from the equation definitely lowers the API design burden.
In many ways its analogous to having language support for strings. In C/C++, you gotta hope that the library you're using has the same approach to strings that you want (std::string? char*, wchar_t?, something else?). In newer languages, it's just a given. (For better or worse: because then you end up stuck with UTF-16 in some languages.)
C also makes you think about ownership in your API design, it's just the language doesn't give you any real tools to express or enforce it. C++ gives you a bunch of tools and options, but you have to hope that you and the API you want to use agreed on which subset of the tools to use.
Garbage collected languages specifically take memory management out of the API design by declaring that the runtime will take care of it for everyone.
If you want lifetime to be something an API can control, then I think Rust's approach makes sense even though it obviously adds complexity. If you don't, then, yes, removing it from the equation definitely lowers the API design burden.
In many ways its analogous to having language support for strings. In C/C++, you gotta hope that the library you're using has the same approach to strings that you want (std::string? char*, wchar_t?, something else?). In newer languages, it's just a given. (For better or worse: because then you end up stuck with UTF-16 in some languages.)