58 lines
1.5 KiB
Rust
58 lines
1.5 KiB
Rust
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// Copyright 2016 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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use std::num::{ParseFloatError, ParseIntError};
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fn main() {
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assert_eq!(simple(), Ok(1));
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assert_eq!(nested(), Ok(2));
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assert_eq!(merge_ok(), Ok(3.0));
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assert_eq!(merge_int_err(), Err(Error::Int));
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assert_eq!(merge_float_err(), Err(Error::Float));
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}
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fn simple() -> Result<i32, ParseIntError> {
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Ok(try!("1".parse()))
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}
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fn nested() -> Result<i32, ParseIntError> {
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Ok(try!(try!("2".parse::<i32>()).to_string().parse::<i32>()))
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}
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fn merge_ok() -> Result<f32, Error> {
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Ok(try!("1".parse::<i32>()) as f32 + try!("2.0".parse::<f32>()))
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}
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fn merge_int_err() -> Result<f32, Error> {
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Ok(try!("a".parse::<i32>()) as f32 + try!("2.0".parse::<f32>()))
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}
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fn merge_float_err() -> Result<f32, Error> {
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Ok(try!("1".parse::<i32>()) as f32 + try!("b".parse::<f32>()))
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}
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#[derive(Debug, PartialEq)]
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enum Error {
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Int,
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Float,
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}
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impl From<ParseIntError> for Error {
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fn from(_: ParseIntError) -> Error {
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Error::Int
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}
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}
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impl From<ParseFloatError> for Error {
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fn from(_: ParseFloatError) -> Error {
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Error::Float
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}
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}
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