Trait rocket::mtls::oid::asn1_rs::nom::lib::std::str::FromStr

1.0.0 · source ·
pub trait FromStr: Sized {
    type Err;

    // Required method
    fn from_str(s: &str) -> Result<Self, Self::Err>;
}
Available on crate feature mtls only.
Expand description

Parse a value from a string

FromStr’s from_str method is often used implicitly, through str’s parse method. See parse’s documentation for examples.

FromStr does not have a lifetime parameter, and so you can only parse types that do not contain a lifetime parameter themselves. In other words, you can parse an i32 with FromStr, but not a &i32. You can parse a struct that contains an i32, but not one that contains an &i32.

§Examples

Basic implementation of FromStr on an example Point type:

use std::str::FromStr;

#[derive(Debug, PartialEq)]
struct Point {
    x: i32,
    y: i32
}

#[derive(Debug, PartialEq, Eq)]
struct ParsePointError;

impl FromStr for Point {
    type Err = ParsePointError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let (x, y) = s
            .strip_prefix('(')
            .and_then(|s| s.strip_suffix(')'))
            .and_then(|s| s.split_once(','))
            .ok_or(ParsePointError)?;

        let x_fromstr = x.parse::<i32>().map_err(|_| ParsePointError)?;
        let y_fromstr = y.parse::<i32>().map_err(|_| ParsePointError)?;

        Ok(Point { x: x_fromstr, y: y_fromstr })
    }
}

let expected = Ok(Point { x: 1, y: 2 });
// Explicit call
assert_eq!(Point::from_str("(1,2)"), expected);
// Implicit calls, through parse
assert_eq!("(1,2)".parse(), expected);
assert_eq!("(1,2)".parse::<Point>(), expected);
// Invalid input string
assert!(Point::from_str("(1 2)").is_err());

Required Associated Types§

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type Err

The associated error which can be returned from parsing.

Required Methods§

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fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

If parsing succeeds, return the value inside Ok, otherwise when the string is ill-formatted return an error specific to the inside Err. The error type is specific to the implementation of the trait.

§Examples

Basic usage with i32, a type that implements FromStr:

use std::str::FromStr;

let s = "5";
let x = i32::from_str(s).unwrap();

assert_eq!(5, x);

Object Safety§

This trait is not object safe.

Implementors§

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impl FromStr for LogLevel

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type Err = &'static str

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impl FromStr for rocket::http::Method

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type Err = ()

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impl FromStr for rocket::serde::json::Value

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type Err = Error

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impl FromStr for IpAddr

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impl FromStr for SocketAddr

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impl FromStr for figment::value::value::Value

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impl FromStr for log::Level

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impl FromStr for log::LevelFilter

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impl FromStr for Month

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impl FromStr for Weekday

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impl FromStr for bool

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impl FromStr for char

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impl FromStr for f32

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impl FromStr for f64

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impl FromStr for i8

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impl FromStr for i16

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impl FromStr for i32

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impl FromStr for i64

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impl FromStr for i128

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impl FromStr for isize

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impl FromStr for u8

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impl FromStr for u16

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impl FromStr for u32

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impl FromStr for u64

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impl FromStr for u128

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impl FromStr for usize

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impl FromStr for ByteUnit

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type Err = Error

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impl FromStr for Accept

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type Err = String

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impl FromStr for ContentType

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type Err = String

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impl FromStr for Cookie<'static>

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type Err = ParseError

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impl FromStr for MediaType

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type Err = String

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impl FromStr for Uuid

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type Err = Error

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impl FromStr for BigInt

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impl FromStr for BigUint

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impl FromStr for String

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impl FromStr for Ipv4Addr

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impl FromStr for Ipv6Addr

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impl FromStr for SocketAddrV4

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impl FromStr for SocketAddrV6

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impl FromStr for NonZero<i8>

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impl FromStr for NonZero<i16>

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impl FromStr for NonZero<i32>

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impl FromStr for NonZero<i64>

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impl FromStr for NonZero<i128>

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impl FromStr for NonZero<isize>

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impl FromStr for NonZero<u8>

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impl FromStr for NonZero<u16>

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impl FromStr for NonZero<u32>

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impl FromStr for NonZero<u64>

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impl FromStr for NonZero<u128>

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impl FromStr for NonZero<usize>

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impl FromStr for OsString

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impl FromStr for PathBuf

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impl FromStr for HeaderName

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impl FromStr for HeaderValue

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impl FromStr for http::method::Method

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impl FromStr for StatusCode

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impl FromStr for Authority

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impl FromStr for PathAndQuery

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impl FromStr for Scheme

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impl FromStr for Uri

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impl FromStr for Mime

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impl FromStr for Number

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type Err = Error

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impl FromStr for Datetime

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type Err = DatetimeParseError

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impl FromStr for Deserializer

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type Err = Error

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impl FromStr for Document

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type Err = TomlError

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impl FromStr for HttpDate

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type Err = Error

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impl FromStr for InlinableString

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impl FromStr for InternalString

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impl FromStr for Item

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type Err = TomlError

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impl FromStr for Key

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type Err = TomlError

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impl FromStr for Level

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type Err = ParseLevelError

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impl FromStr for LevelFilter

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type Err = ParseLevelFilterError

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impl FromStr for Map<String, Value>

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type Err = Error

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impl FromStr for ObjectIdentifier

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type Err = Error

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impl FromStr for Value

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type Err = Error

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impl FromStr for Value

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type Err = TomlError

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impl FromStr for ValueDeserializer

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type Err = Error

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impl<'a> FromStr for Oid<'a>

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impl<const MIN: i8, const MAX: i8> FromStr for RangedI8<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: i16, const MAX: i16> FromStr for RangedI16<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: i32, const MAX: i32> FromStr for RangedI32<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: i64, const MAX: i64> FromStr for RangedI64<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: i128, const MAX: i128> FromStr for RangedI128<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: isize, const MAX: isize> FromStr for RangedIsize<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: u8, const MAX: u8> FromStr for RangedU8<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: u16, const MAX: u16> FromStr for RangedU16<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: u32, const MAX: u32> FromStr for RangedU32<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: u64, const MAX: u64> FromStr for RangedU64<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: u128, const MAX: u128> FromStr for RangedU128<MIN, MAX>

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type Err = ParseIntError

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impl<const MIN: usize, const MAX: usize> FromStr for RangedUsize<MIN, MAX>

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type Err = ParseIntError