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use core::convert::TryFrom;
use core::fmt;
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub struct BerClassFromIntError(pub(crate) ());
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
#[repr(u8)]
pub enum Class {
Universal = 0b00,
Application = 0b01,
ContextSpecific = 0b10,
Private = 0b11,
}
impl Class {
pub const UNIVERSAL: u8 = 0b00;
pub const APPLICATION: u8 = 0b01;
pub const CONTEXT_SPECIFIC: u8 = 0b10;
pub const PRIVATE: u8 = 0b11;
pub const fn assert_eq(&self, class: Class) -> Result<(), crate::error::Error> {
if *self as u8 == class as u8 {
Ok(())
} else {
Err(crate::error::Error::UnexpectedClass {
expected: Some(class),
actual: *self,
})
}
}
}
impl fmt::Display for Class {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let s = match self {
Class::Universal => "UNIVERSAL",
Class::Application => "APPLICATION",
Class::ContextSpecific => "CONTEXT-SPECIFIC",
Class::Private => "PRIVATE",
};
write!(f, "{}", s)
}
}
impl TryFrom<u8> for Class {
type Error = BerClassFromIntError;
#[inline]
fn try_from(value: u8) -> Result<Self, Self::Error> {
match value {
0b00 => Ok(Class::Universal),
0b01 => Ok(Class::Application),
0b10 => Ok(Class::ContextSpecific),
0b11 => Ok(Class::Private),
_ => Err(BerClassFromIntError(())),
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn methods_class() {
let c = Class::Universal;
assert!(c.assert_eq(Class::Universal).is_ok());
assert!(c.assert_eq(Class::Private).is_err());
assert_eq!(Class::Universal.to_string().as_str(), "UNIVERSAL");
assert_eq!(Class::Application.to_string().as_str(), "APPLICATION");
assert_eq!(
Class::ContextSpecific.to_string().as_str(),
"CONTEXT-SPECIFIC"
);
assert_eq!(Class::Private.to_string().as_str(), "PRIVATE");
assert!(Class::try_from(0b00).is_ok());
assert!(Class::try_from(0b01).is_ok());
assert!(Class::try_from(0b10).is_ok());
assert!(Class::try_from(0b11).is_ok());
assert!(Class::try_from(4).is_err());
}
}