Trait Backend 

pub trait Backend<T>
where
    T: ScalarBase,
{
    const MATERIALIZES_CONJ: bool;
    const REQUIRES_UNIT_STRIDE: bool;

    // Required method
    fn bgemm_contiguous_into(
        c: &mut ContiguousOperandMut<T>,
        a: &ContiguousOperand<T>,
        b: &ContiguousOperand<T>,
        batch_dims: &[usize],
        m: usize,
        n: usize,
        k: usize,
        alpha: T,
        beta: T,
    ) -> Result<(), StridedError>;
}

Trait for backends that can execute batched GEMM on contiguous operands.

Each backend declares its configuration (conjugation materialization, stride requirements) and provides a GEMM implementation.

Implementations are provided by each backend module (faer, blas). External crates can implement this trait for custom scalar types (e.g., tropical semiring) and pass the backend to einsum2_with_backend_into.

Required Associated Constants

const MATERIALIZES_CONJ: bool

Whether the backend needs conjugation materialized into the data before GEMM (e.g., CBLAS has no conjugation flag for ?gemm).

const REQUIRES_UNIT_STRIDE: bool

Whether the backend requires at least one unit stride per matrix dimension (row or column stride must be 1). CBLAS ?gemm requires this; faer does not.

Required Methods

fn bgemm_contiguous_into( c: &mut ContiguousOperandMut<T>, a: &ContiguousOperand<T>, b: &ContiguousOperand<T>, batch_dims: &[usize], m: usize, n: usize, k: usize, alpha: T, beta: T, ) -> Result<(), StridedError>

Execute batched GEMM: C = alpha * A * B + beta * C for each batch.

• c: mutable output operand (batch x m x n)
• a: input operand (batch x m x k)
• b: input operand (batch x k x n)
• batch_dims: sizes of the batch dimensions
• m, n, k: fused matrix dimensions
• alpha, beta: scaling factors

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<T> Backend<T> for FaerBackend

where T: ScalarBase + ElementOpApply + ComplexField,

const MATERIALIZES_CONJ: bool = false

const REQUIRES_UNIT_STRIDE: bool = false

impl<T> Backend<T> for NaiveBackend

where T: ScalarBase + ElementOpApply,

const MATERIALIZES_CONJ: bool = false

const REQUIRES_UNIT_STRIDE: bool = false