Teuchos_as.hpp

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#ifndef TEUCHOS_AS_HPP
#define TEUCHOS_AS_HPP

#include "Teuchos_Assert.hpp"
#include <limits>

#ifdef HAVE_TEUCHOS_QD
#include <qd/qd_real.h>
#include <qd/dd_real.h>
#endif

namespace Teuchos {


template<class TypeTo, class TypeFrom>
class ValueTypeConversionTraits {
public:
  static TypeTo convert (const TypeFrom t) {
    // This default implementation is just an implicit conversion and
    // may generate compiler warnings on dangerous conversions.
    return t;
  }

  static TypeTo safeConvert (const TypeFrom t) {
    // This default implementation is just an implicit conversion and
    // may generate compiler warnings on dangerous conversions.  No
    // runtime checking (e.g., for overflow) can be done by default;
    // only specializations can define meaningful and portable
    // run-time checks of conversions.
    return t;
  }
};

template<class TypeTo, class TypeFrom>
inline TypeTo as( const TypeFrom& t )
{
#ifdef HAVE_TEUCHOS_DEBUG
  return ValueTypeConversionTraits<TypeTo,TypeFrom>::safeConvert(t);
#else
  return ValueTypeConversionTraits<TypeTo,TypeFrom>::convert(t);
#endif // HAVE_TEUCHOS_DEBUG
}


template<class TypeTo, class TypeFrom>
inline TypeTo asSafe( const TypeFrom& t )
{
  return ValueTypeConversionTraits<TypeTo,TypeFrom>::safeConvert(t);
}


template <class TypeTo>
class asFunc {
  public:
  asFunc() {}

  template <class TypeFrom>
  inline TypeTo operator()(const TypeFrom &t) {
    return as<TypeTo>(t);
  }
};


//
// Standard specializations of ValueTypeConversionTraits
//

template<>
class ValueTypeConversionTraits<int, double> {
public:
  static int convert (const double t) {
    // Implicit conversion from double to int causes compiler
    // warnings, but static_cast does not.
    return static_cast<int> (t);
  }

  static int safeConvert (const double t) {
    const int minInt = std::numeric_limits<int>::min ();
    const int maxInt = std::numeric_limits<int>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<double> (minInt) || t > static_cast<double> (maxInt),
      std::range_error,
      "Teuchos::ValueTypeConversionTraits<int, double>::safeConvert: "
      "Input double t = " << t << " is out of the valid range [" << minInt
      << ", " << maxInt << "] for conversion to int.");
    return static_cast<int> (t);
  }
};

template<>
class ValueTypeConversionTraits<int, float> {
public:
  static int convert (const float t) {
    // Implicit conversion from float to int may cause compiler
    // warnings, but static_cast does not.  Note that casting from
    // (32-bit) float to (32-bit signed) int can never overflow.
    return static_cast<int> (t);
  }

  static int safeConvert (const float t) {
    // Implicit conversion from float to int may cause compiler
    // warnings, but static_cast does not.  Note that casting from
    // (32-bit) float to (32-bit signed) int can never overflow.
    return static_cast<int> (t);
  }
};


#ifdef HAVE_TEUCHOS_LONG_LONG_INT

template<>
class ValueTypeConversionTraits<float, long long> {
public:
  static float convert (const long long t) {
    // Implicit conversion from long long to float may cause compiler
    // warnings, but static_cast does not.
    return static_cast<float> (t);
  }

  static float safeConvert (const long long t) {
    const float minFloat = std::numeric_limits<float>::min ();
    const float maxFloat = std::numeric_limits<float>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<long long> (minFloat) ||
      t > static_cast<long long> (maxFloat),
      std::range_error,
      "Teuchos::ValueTypeConversionTraits<float, long long>::safeConvert: "
      "Input long long t = " << t << " is out of the valid range [" << minFloat
      << ", " << maxFloat << "] for conversion to float.");

    // Implicit conversion from long long to float may cause compiler
    // warnings, but static_cast does not.
    return static_cast<float> (t);
  }
};

template<>
class ValueTypeConversionTraits<float, unsigned long long> {
public:
  static float convert (const unsigned long long t) {
    // Implicit conversion from unsigned long long to float may cause
    // compiler warnings, but static_cast does not.
    return static_cast<float> (t);
  }

  static float safeConvert (const unsigned long long t) {
    const float minFloat = std::numeric_limits<float>::min ();
    const float maxFloat = std::numeric_limits<float>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<unsigned long long> (minFloat) ||
      t > static_cast<unsigned long long> (maxFloat),
      std::invalid_argument,
      "Teuchos::ValueTypeConversionTraits<float, unsigned long long>::safeConvert: "
      "Input unsigned long long t = " << t << " is out of the valid range [" << minFloat
      << ", " << maxFloat << "] for conversion to float.");

    // Implicit conversion from unsigned long long to float may cause
    // compiler warnings, but static_cast does not.
    return static_cast<float> (t);
  }
};

template<>
class ValueTypeConversionTraits<int, long long> {
public:
  static int convert (const long long t) {
    // Implicit conversion from long long to int may cause compiler
    // warnings, but static_cast does not.
    return static_cast<int> (t);
  }

  static int safeConvert (const long long t) {
    const int minInt = std::numeric_limits<int>::min ();
    const int maxInt = std::numeric_limits<int>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<long long> (minInt) ||
      t > static_cast<long long> (maxInt),
      std::range_error,
      "Teuchos::ValueTypeConversionTraits<int, long long>::safeConvert: "
      "Input long long t = " << t << " is out of the valid range [" << minInt
      << ", " << maxInt << "] for conversion to int.");

    // Implicit conversion from long long to int may cause compiler
    // warnings, but static_cast does not.
    return static_cast<int> (t);
  }
};


template<>
class ValueTypeConversionTraits<unsigned int, long long> {
public:
  static unsigned int convert (const long long t) {
    // Implicit conversion from long long to unsigned int may cause
    // compiler warnings, but static_cast does not.
    return static_cast<unsigned int> (t);
  }

  static unsigned int safeConvert (const long long t) {
    const unsigned int minInt = std::numeric_limits<unsigned int>::min ();
    const unsigned int maxInt = std::numeric_limits<unsigned int>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<long long> (minInt) ||
      t > static_cast<long long> (maxInt),
      std::range_error,
      "Teuchos::ValueTypeConversionTraits<unsigned int, long long>::safeConvert: "
      "Input long long t = " << t << " is out of the valid range [" << minInt
      << ", " << maxInt << "] for conversion to unsigned int.");

    // Implicit conversion from long long to unsigned int may cause
    // compiler warnings, but static_cast does not.
    return static_cast<unsigned int> (t);
  }
};

template<>
class ValueTypeConversionTraits<int, unsigned long long> {
public:
  static int convert (const unsigned long long t) {
    // Implicit conversion from unsigned long long to int may cause
    // compiler warnings, but static_cast does not.
    return static_cast<int> (t);
  }

  static int safeConvert (const unsigned long long t) {
    const int minInt = std::numeric_limits<int>::min ();
    const int maxInt = std::numeric_limits<int>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<unsigned long long> (minInt) ||
      t > static_cast<unsigned long long> (maxInt),
      std::invalid_argument,
      "Teuchos::ValueTypeConversionTraits<int, unsigned long long>::safeConvert: "
      "Input unsigned long long t = " << t << " is out of the valid range [" << minInt
      << ", " << maxInt << "] for conversion to int.");

    // Implicit conversion from unsigned long long to int may cause
    // compiler warnings, but static_cast does not.
    return static_cast<int> (t);
  }
};

template<>
class ValueTypeConversionTraits<unsigned int, unsigned long long> {
public:
  static unsigned int convert (const unsigned long long t) {
    // Implicit conversion from unsigned long long to unsigned int may
    // cause compiler warnings, but static_cast does not.
    return static_cast<unsigned int> (t);
  }

  static unsigned int safeConvert (const unsigned long long t) {
    const unsigned int minInt = std::numeric_limits<unsigned int>::min ();
    const unsigned int maxInt = std::numeric_limits<unsigned int>::max ();

    TEUCHOS_TEST_FOR_EXCEPTION(
      t < static_cast<unsigned long long> (minInt) ||
      t > static_cast<unsigned long long> (maxInt),
      std::invalid_argument,
      "Teuchos::ValueTypeConversionTraits<unsigned int, unsigned long long>::safeConvert: "
      "Input unsigned long long t = " << t << " is out of the valid range [" << minInt
      << ", " << maxInt << "] for conversion to unsigned int.");

    // Implicit conversion from unsigned long long to unsigned int may
    // cause compiler warnings, but static_cast does not.
    return static_cast<unsigned int> (t);
  }
};

#endif // HAVE_TEUCHOS_LONG_LONG_INT


template<int N>
class ValueTypeConversionTraits<std::string, char[N]> {
public:
  static std::string convert( const char t[] )
    { return std::string(t); }
  static std::string safeConvert( const char t[] )
    { return std::string(t); }
};

#ifdef HAVE_TEUCHOS_QD

template <>
class ValueTypeConversionTraits<double, qd_real> {
public:
  inline static double convert( const qd_real t )
    { return to_double(t); }
  inline static double safeConvert( const qd_real t )
    { return to_double(t); }
};

template <>
class ValueTypeConversionTraits<float, qd_real> {
public:
  inline static float convert( const qd_real t )
    { return (float)to_double(t); }
  inline static float safeConvert( const qd_real t )
    { return (float)to_double(t); }
};

template <>
class ValueTypeConversionTraits<int, qd_real> {
public:
  inline static int convert( const qd_real t )
    { return to_int(t); }
  inline static int safeConvert( const qd_real t )
    { return to_int(t); }
};

template <>
class ValueTypeConversionTraits<dd_real, qd_real> {
public:
  inline static dd_real convert( const qd_real t )
    { return to_dd_real(t); }
  inline static dd_real safeConvert( const qd_real t )
    { return to_dd_real(t); }
};

template <>
class ValueTypeConversionTraits<double, dd_real> {
public:
  inline static double convert( const dd_real t )
    { return to_double(t); }
  inline static double safeConvert( const dd_real t )
    { return to_double(t); }
};

template <>
class ValueTypeConversionTraits<float, dd_real> {
public:
  inline static float convert( const dd_real t )
    { return (float)to_double(t); }
  inline static float safeConvert( const dd_real t )
    { return (float)to_double(t); }
};

template <>
class ValueTypeConversionTraits<int, dd_real> {
public:
  inline static int convert( const dd_real t )
    { return to_int(t); }
  inline static int safeConvert( const dd_real t )
    { return to_int(t); }
};

template <>
class ValueTypeConversionTraits<qd_real, long unsigned int> {
public:
  inline static qd_real convert( const long unsigned int t )
    { return ValueTypeConversionTraits<qd_real,int>::convert(ValueTypeConversionTraits<int,long unsigned int>::convert(t)); }
  inline static qd_real safeConvert( const long unsigned int t )
    { return ValueTypeConversionTraits<qd_real,int>::safeConvert(ValueTypeConversionTraits<int,long unsigned int>::safeConvert(t)); }
};

template <>
class ValueTypeConversionTraits<dd_real, long unsigned int> {
public:
  inline static dd_real convert( const long unsigned int t )
    { return ValueTypeConversionTraits<dd_real,int>::convert(ValueTypeConversionTraits<int,long unsigned int>::convert(t)); }
  inline static dd_real safeConvert( const long unsigned int t )
    { return ValueTypeConversionTraits<dd_real,int>::safeConvert(ValueTypeConversionTraits<int,long unsigned int>::safeConvert(t)); }
};

#endif // HAVE_TEUCHOS_QD

// ToDo: Add more specializations as needed!


} // end namespace Teuchos


#endif // TEUCHOS_AS_HPP