random.tcc (cauchy_distribution<>:: operator()(_UniformRandomNumberGenerator&,…

random.tcc (cauchy_distribution<>:: operator()(_UniformRandomNumberGenerator&, const param_type&)): Avoid M_PI, a glibc extension.

2009-05-14  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/bits/random.tcc (cauchy_distribution<>::
	operator()(_UniformRandomNumberGenerator&, const param_type&)): 
	Avoid M_PI, a glibc extension.

From-SVN: r147521

libstdc++-v3/ChangeLog

+2009-05-14  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/bits/random.tcc (cauchy_distribution<>::
+	operator()(_UniformRandomNumberGenerator&, const param_type&)): 
+	Avoid M_PI, a glibc extension.
+
 2009-05-13  Ben Elliston  <bje@au.ibm.com>
 
 	* include/Makefile.am (PCHFLAGS): Remove -Winvalid-pch.

libstdc++-v3/include/bits/random.tcc

@@ -1653,12 +1653,11 @@ namespace std
 	  __aurng(__urng);
 	_RealType __u;
 	do
-	  {
-	    __u = __aurng();
-	  }
+	  __u = __aurng();
 	while (__u == 0.5);
 
-	return __p.a() + __p.b() * std::tan(M_PI * __u);
+	const _RealType __pi = 3.1415926535897932384626433832795029L;
+	return __p.a() + __p.b() * std::tan(__pi * __u);
       }
 
   template<typename _RealType, typename _CharT, typename _Traits>