Pi

pi.c++

    	template <typename T>
    	inlinealways T pi( ) {
    		const static long double p = 3.1415926535897932384626433832795028841971693;
    		return static_cast<T>( p );
    	}
    
    	template <typename T>
    	inlinealways T two_pi( ) {
    		return static_cast<T>( pi<long double>( ) * 2 );
    	}
    
    	template <typename T>
    	inlinealways T root_two_pi( ) {
    		const static long double r2pi = 2.50662827463;
    		return static_cast<T>( r2pi );
    	}
    
    	template <typename T>
    	inlinealways T root_pi( ) {
    		const static long double rpi = 1.77245385091;
    		return static_cast<T>( rpi );
    	}
    
    	template <typename T>
    	inlinealways T inverse_pi( ) {
    		return static_cast<T>( 1 / pi<long double>( ) );
    	}
    
    	template <typename T>
    	inlinealways T inverse_two_pi( ) {
    		return static_cast<T>( 1 / two_pi<long double>( ) );
    	}
    
    	template <typename T>
    	inlinealways T half_pi( ) {
    		return static_cast<T>( pi<long double>( ) / 2 );
    	}
    
    	template <typename T>
    	inlinealways T quarter_pi( ) {
    		return static_cast<T>( pi<long double>( ) / 4 );
    	}