[boost] [Math] Making math compile on C99 archs with no long double

Subject: [boost] [Math] Making math compile on C99 archs with no long double
From: Seth LaForge (sethml_at_[hidden])
Date: 2009-04-20 21:59:03

In trying to compile Boost 1.38.0 for arm/gcc-4.1.2, which has no long
double support, I ran into the following compile error:
./boost/math/special_functions/expm1.hpp: In function ‘long double
boost::math::expm1(long double, const
boost::math::policies::policy<boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy,
boost::math::policies::default_policy>&)’:
./boost/math/special_functions/expm1.hpp:270: error: ‘::expm1l’ has
not been declared

The fix is simple - the expm1.hpp is trying to use a long double C99
function despite BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS being
defined.

The following patch (also attached in case gmail mangles it) fixes the problem:

diff -r -u boost_1_38_0.orig/boost/math/special_functions/expm1.hpp
boost_1_38_0/boost/math/special_functions/expm1.hpp
--- boost_1_38_0.orig/boost/math/special_functions/expm1.hpp
2009-01-07 08:37:59.000000000 -0800
+++ boost_1_38_0/boost/math/special_functions/expm1.hpp 2009-04-20
18:24:33.312485307 -0700
@@ -267,10 +267,12 @@
 #if defined(BOOST_HAS_EXPM1) && !(defined(__osf__) && defined(__DECCXX_VER))
 #  ifdef BOOST_MATH_USE_C99
 inline float expm1(float x, const policies::policy<>&){ return ::expm1f(x); }
+#    ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
 inline long double expm1(long double x, const policies::policy<>&){
return ::expm1l(x); }
-#else
+#    endif
+#  else
 inline float expm1(float x, const policies::policy<>&){ return ::expm1(x); }
-#endif
+#  endif
 inline double expm1(double x, const policies::policy<>&){ return ::expm1(x); }
 #endif