max@0: // Copyright (C) 2009-2010 NICTA (www.nicta.com.au)
max@0: // Copyright (C) 2009-2010 Conrad Sanderson
max@0: // 
max@0: // This file is part of the Armadillo C++ library.
max@0: // It is provided without any warranty of fitness
max@0: // for any purpose. You can redistribute this file
max@0: // and/or modify it under the terms of the GNU
max@0: // Lesser General Public License (LGPL) as published
max@0: // by the Free Software Foundation, either version 3
max@0: // of the License or (at your option) any later version.
max@0: // (see http://www.opensource.org/licenses for more info)
max@0: 
max@0: 
max@0: //! \addtogroup upgrade_val
max@0: //! @{
max@0: 
max@0: 
max@0: 
max@0: //! upgrade_val is used to ensure an operation such as multiplication is possible between two types.
max@0: //! values are upgraded only where necessary.
max@0: 
max@0: template<typename T1, typename T2>
max@0: struct upgrade_val
max@0:   {
max@0:   typedef typename promote_type<T1,T2>::result T1_result;
max@0:   typedef typename promote_type<T1,T2>::result T2_result;
max@0:   
max@0:   arma_inline
max@0:   static
max@0:   typename promote_type<T1,T2>::result
max@0:   apply(const T1 x)
max@0:     {
max@0:     typedef typename promote_type<T1,T2>::result out_type;
max@0:     return out_type(x);
max@0:     }
max@0:   
max@0:   arma_inline
max@0:   static
max@0:   typename promote_type<T1,T2>::result
max@0:   apply(const T2 x)
max@0:     {
max@0:     typedef typename promote_type<T1,T2>::result out_type;
max@0:     return out_type(x);
max@0:     }
max@0:   
max@0:   };
max@0: 
max@0: 
max@0: // template<>
max@0: template<typename T>
max@0: struct upgrade_val<T,T>
max@0:   {
max@0:   typedef T T1_result;
max@0:   typedef T T2_result;
max@0:   
max@0:   arma_inline static const T& apply(const T& x) { return x; }
max@0:   };
max@0: 
max@0: 
max@0: //! upgrade a type to allow multiplication with a complex type
max@0: //! e.g. the int in "int * complex<double>" is upgraded to a double
max@0: // template<>
max@0: template<typename T, typename T2>
max@0: struct upgrade_val< std::complex<T>, T2 >
max@0:   {
max@0:   typedef std::complex<T> T1_result;
max@0:   typedef T               T2_result;
max@0:   
max@0:   arma_inline static const std::complex<T>& apply(const std::complex<T>& x) { return x;    }
max@0:   arma_inline static       T                apply(const T2 x)               { return T(x); }
max@0:   };
max@0: 
max@0: 
max@0: // template<>
max@0: template<typename T1, typename T>
max@0: struct upgrade_val< T1, std::complex<T> >
max@0:   {
max@0:   typedef T               T1_result;
max@0:   typedef std::complex<T> T2_result;
max@0:   
max@0:   arma_inline static       T                apply(const T1 x)               { return T(x); }
max@0:   arma_inline static const std::complex<T>& apply(const std::complex<T>& x) { return x;    }
max@0:   };
max@0: 
max@0: 
max@0: //! ensure we don't lose precision when multiplying a complex number with a higher precision real number
max@0: template<>
max@0: struct upgrade_val< std::complex<float>, double >
max@0:   {
max@0:   typedef std::complex<double> T1_result;
max@0:   typedef double               T2_result;
max@0:   
max@0:   arma_inline static const std::complex<double> apply(const std::complex<float>& x) { return std::complex<double>(x); }
max@0:   arma_inline static       double               apply(const double x)               { return x; }
max@0:   };
max@0: 
max@0: 
max@0: template<>
max@0: struct upgrade_val< double, std::complex<float> >
max@0:   {
max@0:   typedef double              T1_result;
max@0:   typedef std::complex<float> T2_result;
max@0:   
max@0:   arma_inline static       double               apply(const double x)               { return x; }
max@0:   arma_inline static const std::complex<double> apply(const std::complex<float>& x) { return std::complex<double>(x); }
max@0:   };
max@0: 
max@0: 
max@0: //! ensure we don't lose precision when multiplying complex numbers with different underlying types
max@0: template<>
max@0: struct upgrade_val< std::complex<float>, std::complex<double> >
max@0:   {
max@0:   typedef std::complex<double> T1_result;
max@0:   typedef std::complex<double> T2_result;
max@0:   
max@0:   arma_inline static const std::complex<double>  apply(const std::complex<float>&  x) { return std::complex<double>(x); }
max@0:   arma_inline static const std::complex<double>& apply(const std::complex<double>& x) { return x; }
max@0:   };
max@0: 
max@0: 
max@0: template<>
max@0: struct upgrade_val< std::complex<double>, std::complex<float> >
max@0:   {
max@0:   typedef std::complex<double> T1_result;
max@0:   typedef std::complex<double> T2_result;
max@0:   
max@0:   arma_inline static const std::complex<double>& apply(const std::complex<double>& x) { return x; }
max@0:   arma_inline static const std::complex<double>  apply(const std::complex<float>&  x) { return std::complex<double>(x); }
max@0:   };
max@0: 
max@0: 
max@0: //! work around limitations in the complex class (at least as present in gcc 4.1 & 4.3)
max@0: template<>
max@0: struct upgrade_val< std::complex<double>, float >
max@0:   {
max@0:   typedef std::complex<double> T1_result;
max@0:   typedef double               T2_result;
max@0:   
max@0:   arma_inline static const std::complex<double>& apply(const std::complex<double>& x) { return x; }
max@0:   arma_inline static       double                apply(const float x)                 { return double(x); }
max@0:   };
max@0: 
max@0: 
max@0: template<>
max@0: struct upgrade_val< float, std::complex<double> >
max@0:   {
max@0:   typedef double               T1_result;
max@0:   typedef std::complex<double> T2_result;
max@0:   
max@0:   arma_inline static       double                apply(const float x)                 { return double(x); }
max@0:   arma_inline static const std::complex<double>& apply(const std::complex<double>& x) { return x; }
max@0:   };
max@0: 
max@0: 
max@0: 
max@0: //! @}