Chris@16: //  (C) Copyright John Maddock 2005.
Chris@16: //  Use, modification and distribution are subject to the
Chris@16: //  Boost Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_MATH_COMPLEX_ACOSH_INCLUDED
Chris@16: #define BOOST_MATH_COMPLEX_ACOSH_INCLUDED
Chris@16: 
Chris@16: #ifndef BOOST_MATH_COMPLEX_DETAILS_INCLUDED
Chris@16: #  include <boost/math/complex/details.hpp>
Chris@16: #endif
Chris@16: #ifndef BOOST_MATH_COMPLEX_ATANH_INCLUDED
Chris@16: #  include <boost/math/complex/acos.hpp>
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost{ namespace math{
Chris@16: 
Chris@16: template<class T> 
Chris@16: inline std::complex<T> acosh(const std::complex<T>& z)
Chris@16: {
Chris@16:    //
Chris@16:    // We use the relation acosh(z) = +-i acos(z)
Chris@16:    // Choosing the sign of multiplier to give real(acosh(z)) >= 0
Chris@16:    // as well as compatibility with C99.
Chris@16:    //
Chris@16:    std::complex<T> result = boost::math::acos(z);
Chris@16:    if(!(boost::math::isnan)(result.imag()) && signbit(result.imag()))
Chris@16:       return detail::mult_i(result);
Chris@16:    return detail::mult_minus_i(result);
Chris@16: }
Chris@16: 
Chris@16: } } // namespaces
Chris@16: 
Chris@16: #endif // BOOST_MATH_COMPLEX_ACOSH_INCLUDED