shrink_custom_checked

morton_encoding

Function shrink_custom_checked 

Source 
pub fn shrink_custom_checked<Coor, Key>(
    x: Key,
    siz_rat: NonZeroUsize,
) -> Option<Coor>
where
    Coor: ToPrimitive + PrimInt,
    Key: ValidKey<Coor>,
Expand description

Fallibly “shrinks” a given number, only keeping a certain amount of its bits.

The 0th bit is always kept, and so is every siz_ratth bit thereafter. All other bits are lost. Alternatively, if the provided Key type is too small to fit siz_rat Coor numbers inside it, a None is returned .

This function is usable when the size ratio is computed at run-time, but bear in mind that it might run much more slowly than its compile-time counterparts.

This function sanitises its input, so the bits that are thrown away do not need to be cleared by the user.

§Examples

assert_eq!(shrink_custom_checked::<u16, u32>(0xFFFF_FFFF, nz(2)), Some(0xFFFF));
assert_eq!(shrink_custom_checked::<u16, u32>(0x185185, nz(3)), None);