Author here. I hear what you're saying. But there's lots of times while using rust where the language supports feature X and feature Y, but the features can't be used together.
For example, you can write functions which return an impl Trait. And structs can contain arbitrary fields. But you can't write a struct which contains a value returned via impl Trait - because you can't name the type.
Or, I can write if a && b. And I can write if let Some(x) = x. But I can't combine those features together to write if let Some(x) = x && b.
I want things like this to be fixed. Do I want rust to be "bigger"? I mean, measured by the number of lines in the compiler, probably yeah? But measured from the point of view of "how complex is rust to learn and use", feature holes make the language more complex. Fixing these problems would make the language simpler to learn and simpler to use, because developers don't have to remember as much stuff. You can just program the obvious way.
Pin didn't take much work to implement in the standard library. But its not a "lean" feature. It takes a massive cognitive burden to use - to say nothing of how complex code that uses it becomes. I'd rather clean, simple, easy to read rust code and a complex borrow checker than a simple compiler and hard to use language.
For example, you can write functions which return an impl Trait. And structs can contain arbitrary fields. But you can't write a struct which contains a value returned via impl Trait - because you can't name the type.
Or, I can write if a && b. And I can write if let Some(x) = x. But I can't combine those features together to write if let Some(x) = x && b.
I want things like this to be fixed. Do I want rust to be "bigger"? I mean, measured by the number of lines in the compiler, probably yeah? But measured from the point of view of "how complex is rust to learn and use", feature holes make the language more complex. Fixing these problems would make the language simpler to learn and simpler to use, because developers don't have to remember as much stuff. You can just program the obvious way.
Pin didn't take much work to implement in the standard library. But its not a "lean" feature. It takes a massive cognitive burden to use - to say nothing of how complex code that uses it becomes. I'd rather clean, simple, easy to read rust code and a complex borrow checker than a simple compiler and hard to use language.