Enum Evolution 

pub enum Evolution {
    InitialVersion,
    FieldAdded {
        name: String,
    },
    FieldMadeOptional {
        name: String,
    },
    FieldRemoved {
        name: String,
    },
    FieldMadeTransient {
        name: String,
    },
}

Variants

InitialVersion

FieldAdded

Add a new field to a struct.

New version can still read the old with the use of default. Old version can only read if the type is Option<T> and the value is None.

Fields

name: String

FieldMadeOptional

Existing non-option field is made optional.

New version can read old data by wrapping with Some. Old version can read new data if it is not None.

Fields

name: String

FieldRemoved

Field removed from a struct.

New version can read old data by skipping the field. Old version can read new data only if it was Option<T>.

Fields

name: String

FieldMadeTransient

Field made transient.

An alias for FieldRemoved.

Fields

name: String

Trait Implementations

impl Debug for Evolution

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

Formats the value using the given formatter.