Function contract_pair 

pub fn contract_pair(
    lhs: &IdxTensor,
    rhs: &IdxTensor,
) -> Result<IdxTensor, IdxTensorError>

Contract two tensors with the default pairwise semantics.

This is the concrete IdxTensor entry point for binary contraction. It contracts all common indices and preserves the pairwise structured fast paths used by [TensorContractionLike::contract_pair].

Errors

Returns an error when the pair is disconnected or has incompatible indices /// (a shape or index mismatch), or when the contraction reports a failure (a /// backend failure).