mirror of
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53 lines
1.6 KiB
Rust
53 lines
1.6 KiB
Rust
// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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trait to_str {
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fn to_string_(&self) -> String;
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}
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impl to_str for int {
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fn to_string_(&self) -> String { self.to_string() }
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}
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impl to_str for String {
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fn to_string_(&self) -> String { self.clone() }
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}
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impl to_str for () {
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fn to_string_(&self) -> String { "()".to_string() }
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}
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trait map<T> {
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fn map<U, F>(&self, f: F) -> Vec<U> where F: FnMut(&T) -> U;
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}
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impl<T> map<T> for Vec<T> {
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fn map<U, F>(&self, mut f: F) -> Vec<U> where F: FnMut(&T) -> U {
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let mut r = Vec::new();
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for i in self.iter() {
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r.push(f(i));
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}
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r
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}
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}
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fn foo<U, T: map<U>>(x: T) -> Vec<String> {
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x.map(|_e| "hi".to_string() )
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}
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fn bar<U:to_str,T:map<U>>(x: T) -> Vec<String> {
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x.map(|_e| _e.to_string_() )
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}
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pub fn main() {
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assert_eq!(foo(vec!(1)), vec!("hi".to_string()));
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assert_eq!(bar::<int, Vec<int> >(vec!(4, 5)), vec!("4".to_string(), "5".to_string()));
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assert_eq!(bar::<String, Vec<String> >(vec!("x".to_string(), "y".to_string())),
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vec!("x".to_string(), "y".to_string()));
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assert_eq!(bar::<(), Vec<()>>(vec!(())), vec!("()".to_string()));
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}
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