PowFast.h

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/*------------------------------------------------------------------------------

   HXA7241 General library.
   Harrison Ainsworth / HXA7241 : 2004-2011

   http://www.hxa.name/

------------------------------------------------------------------------------*/


#ifndef LSST_UTILS_POWFAST_H
#define LSST_UTILS_POWFAST_H

namespace lsst { namespace utils {


class PowFast;
template<int> const PowFast& getPowFast(); // forward declaration

class PowFast {
public:
    template<int> friend const PowFast& getPowFast();


    float two(float x                   
             ) const;
    
    float exp(float x                   
           ) const;

    float ten(float x                   
             ) const;

    float r(float logr,                 
            float x                     
           )const;

    unsigned int getPrecision() const;

private:
    explicit PowFast( unsigned int precision = 11 
                    );
    ~PowFast();
    PowFast(const PowFast&);
    PowFast& operator=(const PowFast&);

    unsigned int  precision_m;
    unsigned int* pTable_m;
};

template<int precision /* = 11 */>              // Default values for functions are new in C++11
const PowFast& getPowFast()
{
   static const PowFast k(precision);
   return k;
}
}}
#endif