Enum MAMLVariant 

pub enum MAMLVariant {
    SecondOrder,
    FirstOrder,
    Reptile,
}

Variant of MAML to use.

The variants share the same inner-loop adaptation procedure but differ in how the outer (meta-) gradient is computed.

Variants

SecondOrder

Full MAML with a second-order term. Because OptiRS does not maintain a computation graph, the Hessian-vector product is approximated by a finite difference of inner gradients along the adaptation trajectory. This yields a meta-gradient of the form final_loss_grad - alpha * (g_K - g_0) / K (elementwise) * final_loss_grad, which captures the leading second-order correction without ever instantiating the Hessian.

FirstOrder

First-Order MAML (FOMAML): drops the Hessian term entirely. The meta-gradient is simply final_loss_grad. Cheaper than SecondOrder and usually competitive in practice.

Reptile

Reptile-style update: the meta-gradient is (initial_params - adapted_params) / alpha. No second-order math is required and the resulting direction is empirically similar to FOMAML.

Trait Implementations

impl Clone for MAMLVariant

fn clone(&self) -> MAMLVariant

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for MAMLVariant

impl Debug for MAMLVariant

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

Formats the value using the given formatter.

impl PartialEq for MAMLVariant

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MAMLVariant