1 // ---------------------------------------------------------------------
2 //
3 // Copyright (C) 2018 - 2019 by the deal.II authors
4 //
5 // This file is part of the deal.II library.
6 //
7 // The deal.II library is free software; you can use it, redistribute
8 // it, and/or modify it under the terms of the GNU Lesser General
9 // Public License as published by the Free Software Foundation; either
10 // version 2.1 of the License, or (at your option) any later version.
11 // The full text of the license can be found in the file LICENSE.md at
12 // the top level directory of deal.II.
13 //
14 // ---------------------------------------------------------------------
15 #ifndef dealii_cxx17_cmath_h
16 #define dealii_cxx17_cmath_h
17 
18 #include <deal.II/base/config.h>
19 
20 #ifdef DEAL_II_HAVE_CXX17_BESSEL_FUNCTIONS
21 #  include <cmath>
22 #else
23 #  include <boost/math/special_functions/bessel.hpp>
24 #endif
25 
26 
27 DEAL_II_NAMESPACE_OPEN
28 namespace std_cxx17
29 {
30 #ifndef DEAL_II_HAVE_CXX17_BESSEL_FUNCTIONS
31   double (&cyl_bessel_j)(double,
32                          double) = boost::math::cyl_bessel_j<double, double>;
33   float (&cyl_bessel_jf)(float,
34                          float)  = boost::math::cyl_bessel_j<float, float>;
35 #ifndef __DragonFly__
36   long double (&cyl_bessel_jl)(long double, long double) =
37     boost::math::cyl_bessel_j<long double, long double>;
38 #endif
39 #else
40   using std::cyl_bessel_j;
41   using std::cyl_bessel_jf;
42   using std::cyl_bessel_jl;
43 #endif
44 } // namespace std_cxx17
45 DEAL_II_NAMESPACE_CLOSE
46 
47 #endif // dealii_cxx17_cmath_h
48