Method erf

extern/half/include/half.hpp:1570–1577

Error function implementation. \param arg function argument \return function value stored in single-preicision

			/// \param arg function argument
			/// \return function value stored in single-preicision
			static expr erf(float arg)
			{
			#if HALF_ENABLE_CPP11_CMATH
				return expr(std::erf(arg));
			#else
				return expr(static_cast<float>(erf(static_cast<double>(arg))));
			#endif
			}

			/// Complementary implementation.
			/// \param arg function argument