[Boost-commit] svn:boost r82664 - in trunk: boost/random libs/random/test

Subject: [Boost-commit] svn:boost r82664 - in trunk: boost/random libs/random/test
From: marshall_at_[hidden]
Date: 2013-01-30 01:42:38

Author: marshall
Date: 2013-01-30 01:42:36 EST (Wed, 30 Jan 2013)
New Revision: 82664
URL: http://svn.boost.org/trac/boost/changeset/82664

Log:
Fix behavior with zero seed re: '26.5.3.3 [rand.eng.sub]/7'; thanks to stl_at_microsoft for the report; Refs #7951
Added:
   trunk/libs/random/test/test_zero_seed.cpp   (contents, props changed)
Text files modified: 
   trunk/boost/random/subtract_with_carry.hpp |     4 ++--                                    
   trunk/libs/random/test/Jamfile.v2          |     1 +                                       
   2 files changed, 3 insertions(+), 2 deletions(-)

Modified: trunk/boost/random/subtract_with_carry.hpp
==============================================================================
--- trunk/boost/random/subtract_with_carry.hpp	(original)
+++ trunk/boost/random/subtract_with_carry.hpp	2013-01-30 01:42:36 EST (Wed, 30 Jan 2013)
@@ -161,7 +161,7 @@
                                         IntType, value)
     {
         typedef linear_congruential_engine<uint32_t,40014,0,2147483563> gen_t;
-        gen_t intgen(static_cast<boost::uint32_t>(value));
+        gen_t intgen(static_cast<boost::uint32_t>(value == 0 ? default_seed : value));
         detail::generator_seed_seq<gen_t> gen(intgen);
         seed(gen);
     }
@@ -392,7 +392,7 @@
                                         boost::uint32_t, value)
     {
         typedef linear_congruential_engine<uint32_t, 40014, 0, 2147483563> gen_t;
-        gen_t intgen(value);
+        gen_t intgen(value == 0 ? default_seed : value);
         detail::generator_seed_seq<gen_t> gen(intgen);
         seed(gen);
     }

Modified: trunk/libs/random/test/Jamfile.v2
==============================================================================
--- trunk/libs/random/test/Jamfile.v2	(original)
+++ trunk/libs/random/test/Jamfile.v2	2013-01-30 01:42:36 EST (Wed, 30 Jan 2013)
@@ -53,6 +53,7 @@
 run test_lagged_fibonacci19937.cpp /boost//unit_test_framework ;
 run test_lagged_fibonacci23209.cpp /boost//unit_test_framework ;
 run test_lagged_fibonacci44497.cpp /boost//unit_test_framework ;
+run test_zero_seed.cpp /boost//unit_test_framework ;
 
 # Disable by default.  These don't add much and the larger
 # ones can overflow the stack.

Added: trunk/libs/random/test/test_zero_seed.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/random/test/test_zero_seed.cpp	2013-01-30 01:42:36 EST (Wed, 30 Jan 2013)
@@ -0,0 +1,29 @@
+/*
+	Test case for ticket #7951
+	tests whether or not xxx() == xxx(0) for various engines
+	Thanks to Stephen T. Lavavej for his close reading of 26.5.3.3 [rand.eng.sub]/7 
+*/
+
+#include <boost/random/ranlux.hpp>
+#include <boost/random/linear_congruential.hpp>
+#include <boost/random/mersenne_twister.hpp>
+
+#define BOOST_TEST_MAIN
+#include <boost/test/unit_test.hpp>
+
+#ifdef BOOST_MSVC
+#pragma warning(push)
+#pragma warning(disable:4244)
+#endif
+
+BOOST_AUTO_TEST_CASE(test_zero_seed)
+{
+    BOOST_CHECK(boost::random::ranlux24_base(0) == boost::random::ranlux24_base()); 
+    BOOST_CHECK(boost::random::minstd_rand0(0)  == boost::random::minstd_rand0()); 
+    BOOST_CHECK(boost::random::mt19937(0)       != boost::random::mt19937()); 
+
+    BOOST_CHECK(boost::random::ranlux48_base(0) == boost::random::ranlux48_base ()); 
+
+    BOOST_CHECK(boost::random::ranlux_base_01(0) == boost::random::ranlux_base_01 ()); 
+    BOOST_CHECK(boost::random::ranlux64_base_01(0) == boost::random::ranlux64_base_01 ()); 
+}