35 闭包
Closures are special functions that can capture the variables available in the
surrounding scope. Closures consist of three parts:
- A list of arguments enclosed by pipes
|, these arguments can optionally be
type annotated, but usually the compiler will infer their types
- Optionally the return type using an arrow
->, again this usually gets
inferred
- A block, the last expression is the return value
fn main() {
let captured_value = 7u;
let closure = |argument| {
println!("I captured this: {}", captured_value);
println!("Argument passed was: {}", argument);
true
};
println!("Closure returned: {}", closure("a string"));
}