/// Transforms a value prior to formatting it.
#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq, is_macro::Is)]
#[repr(i8)]
pub enum ConversionFlag {
    /// No conversion
    None = -1, // CPython uses -1
    /// Converts by calling `str(<value>)`.
    Str = b's' as i8,
    /// Converts by calling `ascii(<value>)`.
    Ascii = b'a' as i8,
    /// Converts by calling `repr(<value>)`.
    Repr = b'r' as i8,
}

impl ConversionFlag {
    pub fn to_byte(&self) -> Option<u8> {
        match self {
            Self::None => None,
            flag => Some(*flag as u8),
        }
    }
    pub fn to_char(&self) -> Option<char> {
        Some(self.to_byte()? as char)
    }
}