//! Trust-Exact algorithm trait.
use crateDType;
use Var;
use Result as NumrResult;
use Runtime;
use Tensor;
use ;
use crateOptimizeResult;
/// Trust-Exact: Trust region with nearly-exact subproblem solution.
///
/// Solves the subproblem by finding lambda such that ||(H+lambda*I)^{-1}g|| = delta.
/// Uses Cholesky factorizations. Handles the "hard case".
/// Memory: O(n^2) for full Hessian.