floating-point-operations.hpp

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#pragma once    // Source encoding: UTF-8 with BOM (π is a lowercase Greek "pi").

#include <cppx-core/language/calc/integer-operations.hpp>       // cppx::is_odd
#include <cppx-core/language/syntax/macro-use.hpp>

namespace cppx
{
    namespace impl
    {
        inline auto intpow( const double base, const int exponent )
            -> double
        {
            double result = 1;
            double weight = base;
            for( int n = exponent; n != 0; weight *= weight )
            {
                if( is_odd( n ) )
                {
                    result *= weight;
                    --n;
                }
                else
                {
                    n /= 2;
                }
            }
            return result;
        }
    }  // namespace impl

    template< class Number = double >
    inline auto intpow( const Number base, const int exponent )
        -> Number
    {
        return (0?0
            : exponent == 0?        1.0
            : exponent < 0?         1.0/impl::intpow( base, -exponent )
            :                       impl::intpow( base, exponent )
            );
    }

    inline auto squared( const double x )
        -> double
    { return x*x; }

    inline auto cubed( const double x )
        -> double
    { return x*x*x; }

    namespace calc
    {
        CPPX_USE_CPPX( intpow, squared, cubed );
    }  // namespace math
}  // namespace cppx