Trait DecodeValue 

pub trait DecodeValue<'a>: Sized {
    type Error: Error + From<Error> + 'static;

    // Required method
    fn decode_value<R: Reader<'a>>(
        reader: &mut R,
        header: Header,
    ) -> Result<Self, Self::Error>;
}

DecodeValue trait parses the value part of a Tag-Length-Value object, sans the Tag and Length.

As opposed to Decode, implementer is expected to read the inner content only, without the Header, which was decoded beforehand.

Example

use der::{Decode, DecodeValue, ErrorKind, FixedTag, Header, Reader, Tag};

/// 1-byte month
struct MyByteMonth(u8);

impl<'a> DecodeValue<'a> for MyByteMonth {
    type Error = der::Error;

    fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> der::Result<Self> {
        let month = reader.read_byte()?;
         
        if (0..12).contains(&month) {
            Ok(Self(month))
        } else {
            Err(reader.error(ErrorKind::DateTime))
        }
    }
}

impl FixedTag for MyByteMonth {
    const TAG: Tag = Tag::OctetString;
}

let month = MyByteMonth::from_der(b"\x04\x01\x09").expect("month to decode");

assert_eq!(month.0, 9);

Required Associated Types

type Error: Error + From<Error> + 'static

Type returned in the event of a decoding error.

Required Methods

fn decode_value<R: Reader<'a>>( reader: &mut R, header: Header, ) -> Result<Self, Self::Error>

Attempt to decode this value using the provided Reader.

Errors

Returns Self::Error in the event a decoding error occurred.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'a> DecodeValue<'a> for bool

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for i8

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for i16

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for i32

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for i64

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for i128

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for u8

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for u16

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for u32

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for u64

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for u128

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for ()

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for String

Available on crate feature alloc only.

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a> DecodeValue<'a> for SystemTime

Available on crate feature std only.

type Error = Error

fn decode_value<R: Reader<'a>>(reader: &mut R, header: Header) -> Result<Self>

impl<'a, T> DecodeValue<'a> for Box<T>

where T: DecodeValue<'a>,

Available on crate feature alloc only.

type Error = <T as DecodeValue<'a>>::Error

fn decode_value<R: Reader<'a>>( reader: &mut R, header: Header, ) -> Result<Self, Self::Error>

impl<'a, T> DecodeValue<'a> for Vec<T>

where T: Decode<'a>,

Available on crate feature alloc only.

type Error = <T as Decode<'a>>::Error

fn decode_value<R: Reader<'a>>( reader: &mut R, _header: Header, ) -> Result<Self, Self::Error>

impl<'a, T, E> DecodeValue<'a> for Cow<'a, T>

where T: ToOwned + ?Sized, &'a T: DecodeValue<'a, Error = E>, T::Owned: for<'b> DecodeValue<'b, Error = E>, E: Error + From<Error> + 'static,

Available on crate feature alloc only.

type Error = E

fn decode_value<R: Reader<'a>>( reader: &mut R, header: Header, ) -> Result<Self, Self::Error>

Implementors

impl<'__der> DecodeValue<'__der> for Ia5String

type Error = Error

impl<'__der> DecodeValue<'__der> for PrintableString

type Error = Error

impl<'__der> DecodeValue<'__der> for TeletexString

type Error = Error

impl<'__der: 'a, 'a> DecodeValue<'__der> for Ia5StringRef<'a>

type Error = Error

impl<'__der: 'a, 'a> DecodeValue<'__der> for PrintableStringRef<'a>

type Error = Error

impl<'__der: 'a, 'a> DecodeValue<'__der> for TeletexStringRef<'a>

type Error = Error

impl<'__der: 'a, 'a> DecodeValue<'__der> for Utf8StringRef<'a>

type Error = Error

impl<'__der: 'a, 'a> DecodeValue<'__der> for VideotexStringRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for &'a OctetStringRef

type Error = Error

impl<'a> DecodeValue<'a> for &'a SequenceRef

type Error = Error

impl<'a> DecodeValue<'a> for Any

type Error = Error

impl<'a> DecodeValue<'a> for AnyRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for BitString

type Error = Error

impl<'a> DecodeValue<'a> for BitStringRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for BmpString

type Error = Error

impl<'a> DecodeValue<'a> for GeneralStringRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for GeneralizedTime

type Error = Error

impl<'a> DecodeValue<'a> for Int

type Error = Error

impl<'a> DecodeValue<'a> for IntRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for Null

type Error = Error

impl<'a> DecodeValue<'a> for OctetString

type Error = Error

impl<'a> DecodeValue<'a> for Uint

type Error = Error

impl<'a> DecodeValue<'a> for UintRef<'a>

type Error = Error

impl<'a> DecodeValue<'a> for UtcTime

type Error = Error

impl<'a> DecodeValue<'a> for DateTime

type Error = Error

impl<'a, T> DecodeValue<'a> for SetOfVec<T>

where T: Decode<'a> + DerOrd,

Available on crate feature alloc only.

type Error = <T as Decode<'a>>::Error