Function einsum_with_plan_into 

pub fn einsum_with_plan_into<Alg, Backend>(
    ctx: &mut BackendContext<Alg, Backend>,
    tree: &ContractionTree,
    operands: &[&Tensor<Alg::Scalar>],
    alpha: Alg::Scalar,
    beta: Alg::Scalar,
    output: &mut Tensor<Alg::Scalar>,
    size_dict: Option<&HashMap<u32, usize>>,
) -> Result<()>
where
    Alg: Semiring,
    Alg::Scalar: Scalar + Conjugate + HasAlgebra<Algebra = Alg>,
    Backend: EinsumBackend<Alg>,
    BackendContext<Alg, Backend>: TensorTempPoolContext,

Execute einsum with a pre-optimized ContractionTree, accumulating into an existing output.

Examples

use tenferro_algebra::Standard;
use tenferro_einsum::{einsum_with_plan_into, ContractionTree, Subscripts};
use tenferro_prims::{CpuBackend, CpuContext};

let mut ctx = CpuContext::new(1);
let subs = Subscripts::new(&[&[0, 1], &[1, 2]], &[0, 2]);
let tree = ContractionTree::optimize(&subs, &[&[2, 3], &[3, 4]]).unwrap();
einsum_with_plan_into::<Standard<f64>, CpuBackend>(
    &mut ctx, &tree, &[&a, &b], 1.0, 0.0, &mut c, None,
).unwrap();