mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-22 23:04:33 +00:00
21 lines
539 B
Rust
21 lines
539 B
Rust
pub enum Expr<'var, VAR> {
|
|
Let(Box<Expr<'var, VAR>>,
|
|
Box<dyn for<'v> Fn(Expr<'v, VAR>) -> Expr<'v, VAR> + 'var>)
|
|
}
|
|
|
|
pub fn add<'var, VAR>
|
|
(a: Expr<'var, VAR>, b: Expr<'var, VAR>) -> Expr<'var, VAR> {
|
|
loop {}
|
|
}
|
|
|
|
pub fn let_<'var, VAR, F: for<'v> Fn(Expr<'v, VAR>) -> Expr<'v, VAR>>
|
|
(a: Expr<'var, VAR>, b: F) -> Expr<'var, VAR> {
|
|
loop {}
|
|
}
|
|
|
|
fn main() {
|
|
let ex = |x| { //~ ERROR type annotations needed
|
|
let_(add(x,x), |y| {
|
|
let_(add(x, x), |x|x)})};
|
|
}
|