text: //==============================================================================
  //         Copyright 2003 - 2012   LASMEA UMR 6602 CNRS/Univ. Clermont II
  //         Copyright 2009 - 2012   LRI    UMR 8623 CNRS/Univ Paris Sud XI
  //
  //          Distributed under the Boost Software License, Version 1.0.
  //                 See accompanying file LICENSE.txt or copy at
  //                     http://www.boost.org/LICENSE_1_0.txt
  //==============================================================================
  #define NT2_UNIT_MODULE "nt2 trigonometric toolbox - acos/scalar Mode"
  
  //////////////////////////////////////////////////////////////////////////////
  // unit test behavior of trigonometric components in scalar mode
  //////////////////////////////////////////////////////////////////////////////
  /// created  by jt the 11/02/2011
  ///
  #include <nt2/trigonometric/include/functions/acos.hpp>
  #include <nt2/trigonometric/constants.hpp>
  extern "C" {extern long double cephes_acosl(long double);}
  
  #include <boost/type_traits/is_same.hpp>
  #include <nt2/sdk/functor/meta/call.hpp>
  #include <nt2/sdk/meta/as_integer.hpp>
  #include <nt2/sdk/meta/as_floating.hpp>
  #include <nt2/sdk/meta/as_signed.hpp>
  #include <nt2/sdk/meta/upgrade.hpp>
  #include <nt2/sdk/meta/downgrade.hpp>
  #include <nt2/sdk/meta/scalar_of.hpp>
  #include <boost/dispatch/meta/as_floating.hpp>
  #include <boost/type_traits/common_type.hpp>
  #include <nt2/sdk/unit/tests.hpp>
  #include <nt2/sdk/unit/module.hpp>
  #include <nt2/sdk/memory/buffer.hpp>
  #include <nt2/constant/constant.hpp>
  
  
  NT2_TEST_CASE_TPL ( acos_real__1_0,  NT2_REAL_TYPES)
  {
  
    using nt2::acos;
    using nt2::tag::acos_;
    typedef typename nt2::meta::as_integer<T>::type iT;
    typedef typename nt2::meta::call<acos_(T)>::type r_t;
    typedef typename nt2::meta::scalar_of<r_t>::type ssr_t;
    typedef typename nt2::meta::upgrade<T>::type u_t;
    typedef typename boost::dispatch::meta::as_floating<T>::type wished_r_t;
  
  
    // return type conformity test
    NT2_TEST( (boost::is_same < r_t, wished_r_t >::value) );
    std::cout << std::endl;
  
    // specific values tests
    NT2_TEST_ULP_EQUAL(acos(nt2::Half<T>()), nt2::Pi<r_t>()/3, 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Inf<T>()), nt2::Nan<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Mhalf<T>()), 2*nt2::Pi<r_t>()/3, 0.5);
    NT2_TEST_ULP_EQUAL(acos(nt2::Minf<T>()), nt2::Nan<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Mone<T>()), nt2::Pi<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Nan<T>()), nt2::Nan<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::One<T>()), nt2::Zero<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Zero<T>()), nt2::Pi<r_t>()/2, 0);
  } // end of test for floating_
  
  NT2_TEST_CASE_TPL ( acos_unsigned_int__1_0,  NT2_UNSIGNED_TYPES)
  {
  
    using nt2::acos;
    using nt2::tag::acos_;
    typedef typename nt2::meta::as_integer<T>::type iT;
    typedef typename nt2::meta::call<acos_(T)>::type r_t;
    typedef typename nt2::meta::scalar_of<r_t>::type ssr_t;
    typedef typename nt2::meta::upgrade<T>::type u_t;
    typedef typename boost::dispatch::meta::as_floating<T>::type wished_r_t;
  
  
    // return type conformity test
    NT2_TEST( (boost::is_same < r_t, wished_r_t >::value) );
    std::cout << std::endl;
  
    // specific values tests
    NT2_TEST_ULP_EQUAL(acos(nt2::One<T>()), nt2::Zero<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Zero<T>()), nt2::Pi<r_t>()/2, 0);
  } // end of test for unsigned_int_
  
  NT2_TEST_CASE_TPL ( acos_signed_int__1_0,  NT2_INTEGRAL_SIGNED_TYPES)
  {
  
    using nt2::acos;
    using nt2::tag::acos_;
    typedef typename nt2::meta::as_integer<T>::type iT;
    typedef typename nt2::meta::call<acos_(T)>::type r_t;
    typedef typename nt2::meta::scalar_of<r_t>::type ssr_t;
    typedef typename nt2::meta::upgrade<T>::type u_t;
    typedef typename boost::dispatch::meta::as_floating<T>::type wished_r_t;
  
  
    // return type conformity test
    NT2_TEST( (boost::is_same < r_t, wished_r_t >::value) );
    std::cout << std::endl;
  
    // specific values tests
    NT2_TEST_ULP_EQUAL(acos(nt2::Mone<T>()), nt2::Pi<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::One<T>()), nt2::Zero<r_t>(), 0);
    NT2_TEST_ULP_EQUAL(acos(nt2::Zero<T>()), nt2::Pi<r_t>()/2, 0);
  } // end of test for signed_int_
  