Function cosh

include/half.hpp:3795–3812

Hyperbolic cosine. This function is exact to rounding for all rounding modes. See also:** Documentation for [std::cosh](https://en.cppreference.com/w/cpp/numeric/math/cosh). \param arg function argument \return hyperbolic cosine value of \a arg \exception FE_INVALID for signaling NaN \exception FE_OVERFLOW, ...UNDERFLOW, ...INEXACT according to rounding

	/// \exception FE_INVALID for signaling NaN
	/// \exception FE_OVERFLOW, ...UNDERFLOW, ...INEXACT according to rounding
	inline half cosh(half arg)
	{
	#ifdef HALF_ARITHMETIC_TYPE
		return half(detail::binary, detail::float2half<half::round_style>(std::cosh(detail::half2float<detail::internal_t>(arg.data_))));
	#else
		int abs = arg.data_ & 0x7FFF, exp;
		if(!abs)
			return half(detail::binary, 0x3C00);
		if(abs >= 0x7C00)
			return half(detail::binary, (abs>0x7C00) ? detail::signal(arg.data_) : 0x7C00);
		std::pair<detail::uint32,detail::uint32> mm = detail::hyperbolic_args(abs, exp, (half::round_style==std::round_to_nearest) ? 23 : 26);
		detail::uint32 m = mm.first + mm.second, i = (~m&0xFFFFFFFF) >> 31;
		m = (m>>i) | (m&i) | 0x80000000;
		if((exp+=13+i) > 29)
			return half(detail::binary, detail::overflow<half::round_style>());
		return half(detail::binary, detail::fixed2half<half::round_style,31,false,false,true>(m, exp));
	#endif
	}

	/// Hyperbolic tangent.
	/// This function is exact to rounding for all rounding modes.