I’m struggling with the borrow checker and hope anyone can give me a clue.

The relevant code is below:

// Doc: https://docs.rs/strum/latest/strum/derive.EnumIter.html
use strum_macros::EnumIter;

#[derive(EnumIter, Debug)]
pub enum Frequency {
    Freq1m,
    Freq1h,
    Freq1d,
}

impl Frequency {
    pub fn value(&self) -> i32 {
        match self {
            Frequency::Freq1m => 60,
            Frequency::Freq1h => 3600,
            Frequency::Freq1d => 86400,
        }
    }

    pub fn display_name(&self) -> &'static str {
        match self {
            Frequency::Freq1m => "1m",
            Frequency::Freq1h => "1h",
            Frequency::Freq1d => "1d",
        }
    }
}

impl PartialEq for Frequency {
    fn eq(&self, other: &Self) -> bool {
        self.value() == other.value()
    }
}

for freq in Frequency::iter() {                                          # move occurs
    ui.selectable_value(&mut self.frequency, freq, freq.display_name()); # borrow of moved value
}

After trial and error, I know that if I add the Clone and Copy trait to my Frequency, it will work. But why? My understanding is that the move in for freq in Frenquency::iter() should be fine, right? The later borrow seems valid to me. What am I missing?