Move into version control

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diff --git a/src/armadillo/include/armadillo_bits/fn_hess.hpp b/src/armadillo/include/armadillo_bits/fn_hess.hpp
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+// SPDX-License-Identifier: Apache-2.0
+// 
+// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
+// Copyright 2008-2016 National ICT Australia (NICTA)
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ------------------------------------------------------------------------
+
+
+//! \addtogroup fn_hess
+//! @{
+
+
+template<typename T1>
+inline
+bool
+hess
+  (
+         Mat<typename T1::elem_type>&    H,
+  const Base<typename T1::elem_type,T1>& X,
+  const typename arma_blas_type_only<typename T1::elem_type>::result* junk = nullptr
+  )
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename T1::elem_type eT;
+  
+  Col<eT> tao;
+  
+  const bool status = auxlib::hess(H, X.get_ref(), tao);
+  
+  if(H.n_rows > 2)
+    {
+    for(uword i=0; i < H.n_rows-2; ++i)
+      {
+      H(span(i+2, H.n_rows-1), i).zeros();
+      }
+    }
+  
+  if(status == false)
+    {
+    H.soft_reset();
+    arma_debug_warn_level(3, "hess(): decomposition failed");
+    }
+  
+  return status;
+  }
+
+
+
+template<typename T1>
+arma_warn_unused
+inline
+Mat<typename T1::elem_type>
+hess
+  (
+  const Base<typename T1::elem_type,T1>& X,
+  const typename arma_blas_type_only<typename T1::elem_type>::result* junk = nullptr
+  )
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  typedef typename T1::elem_type eT;
+  
+  Mat<eT> H;
+  Col<eT> tao;
+  
+  const bool status = auxlib::hess(H, X.get_ref(), tao);
+  
+  if(H.n_rows > 2)
+    {
+    for(uword i=0; i < H.n_rows-2; ++i)
+      {
+      H(span(i+2, H.n_rows-1), i).zeros();
+      }
+    }
+  
+  if(status == false)
+    {
+    H.soft_reset();
+    arma_stop_runtime_error("hess(): decomposition failed");
+    }
+  
+  return H;
+  }
+
+
+
+template<typename T1> 
+inline
+bool
+hess
+  (
+         Mat<typename T1::elem_type>&    U,
+         Mat<typename T1::elem_type>&    H,
+  const Base<typename T1::elem_type,T1>& X,
+  const typename arma_blas_type_only<typename T1::elem_type>::result* junk = nullptr
+  )
+  {
+  arma_extra_debug_sigprint();
+  arma_ignore(junk);
+  
+  arma_debug_check( void_ptr(&U) == void_ptr(&H), "hess(): 'U' is an alias of 'H'" );
+  
+  typedef typename T1::elem_type eT;
+  
+  Col<eT> tao;
+  
+  const bool status = auxlib::hess(H, X.get_ref(), tao);
+  
+  if(H.n_rows == 0)
+    {
+    U.reset();
+    }
+  else
+  if(H.n_rows == 1)
+    {
+    U.ones(1, 1);
+    }
+  else
+  if(H.n_rows == 2)
+    {
+    U.eye(2, 2);
+    }
+  else
+    {
+    U.eye(size(H));
+    
+    Col<eT> v;
+    
+    for(uword i=0; i < H.n_rows-2; ++i)
+      {
+      // TODO: generate v in a more efficient manner; 
+      // TODO: the .ones() operation is an overkill, as most of v is overwritten afterwards
+      
+      v.ones(H.n_rows-i-1);
+      
+      v(span(1, H.n_rows-i-2)) = H(span(i+2, H.n_rows-1), i);
+      
+      U(span::all, span(i+1, H.n_rows-1)) -= tao(i) * (U(span::all, span(i+1, H.n_rows-1)) * v * v.t());
+      }
+    
+    U(span::all, H.n_rows-1) = U(span::all, H.n_rows-1) * (eT(1) - tao(H.n_rows-2));
+    
+    for(uword i=0; i < H.n_rows-2; ++i)
+      {
+      H(span(i+2, H.n_rows-1), i).zeros();
+      }
+    }
+  
+  if(status == false)
+    {
+    U.soft_reset();
+    H.soft_reset();
+    arma_debug_warn_level(3, "hess(): decomposition failed");
+    }
+  
+  return status;
+  }
+
+
+
+//! @}