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