Struct FormatVersion 

pub struct FormatVersion {
    pub major: u32,
    pub minor: u32,
}

A parsed MAJOR.MINOR format version.

Compatibility policy

The version gate used to be string equality, which meant a v0.1 reader refused a v0.2 file even when the only change was an added record kind it already knew how to skip. That makes every additive change a breaking one, which defeats the point of having a minor version at all. The rule is now:

• Same major, any minor → readable. Minor bumps are additive-only by contract: new record kinds, new optional fields. An older reader skips what it does not recognise (see AntReader::next_record) and still verifies the trailer, so it gets a truthful subset rather than an error.
• Unknown record kinds are skipped, not fatal — within the same major. They are still hashed, so integrity still holds.
• A different major → rejected, explicitly. A major bump is reserved for changes an old reader would silently MISREAD: changed field meanings, a different container framing, a removed or repurposed kind. Refusing is the only safe answer.
• A newer minor is not an error, but it is a known unknown. AntReader::minor_ahead reports it so a caller can warn that the file may carry records this build did not surface.

Writers must therefore never change the meaning of an existing field within a major. If a change cannot be expressed additively, it needs a major bump.

Fields

major: u32

Major: different majors are mutually unreadable.

minor: u32

Minor: additive-only within a major.

Implementations

impl FormatVersion

pub const CURRENT: FormatVersion

The version this build reads and writes.

pub fn parse(s: &str) -> Option<Self>

Parse "MAJOR.MINOR". A bare "1" is treated as 1.0.

pub fn readable_by_current(&self) -> bool

Can this build read a file written at self?

Trait Implementations

impl Clone for FormatVersion

fn clone(&self) -> FormatVersion

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for FormatVersion

impl Debug for FormatVersion

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for FormatVersion

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for FormatVersion

impl Ord for FormatVersion

fn cmp(&self, other: &FormatVersion) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for FormatVersion

fn eq(&self, other: &FormatVersion) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for FormatVersion

fn partial_cmp(&self, other: &FormatVersion) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for FormatVersion