Attempting to work round the dodgy std::numeric_limits<long double> on

some BSDs.


[SVN r35345]

hash/test/hash_float_test.cpp

@@ -24,12 +24,12 @@ void float_tests(char const* name, T* = 0)
     std::cerr<<"\n"
         <<"Testing " BOOST_STRINGIZE(HASH_NAMESPACE) "::hash<"<<name<<">\n"
         <<"\n"
-        <<"std::numeric_limits<T>::digits = "
+        <<"boost::hash_detail::float_limits<T>::digits = "
-            <<std::numeric_limits<T>::digits<<"\n"
+            <<boost::hash_detail::float_limits<T>::digits<<"\n"
-        <<"std::numeric_limits<int>::digits = "
+        <<"boost::hash_detail::float_limits<int>::digits = "
-            <<std::numeric_limits<int>::digits<<"\n"
+            <<boost::hash_detail::float_limits<int>::digits<<"\n"
-        <<"std::numeric_limits<std::size_t>::digits = "
+        <<"boost::hash_detail::float_limits<std::size_t>::digits = "
-            <<std::numeric_limits<std::size_t>::digits<<"\n"
+            <<boost::hash_detail::float_limits<std::size_t>::digits<<"\n"
         <<"\n"
         ;
 
@@ -50,11 +50,11 @@ void float_tests(char const* name, T* = 0)
 #if defined(__BORLANDC__)
     std::cerr<<"Not running infinity checks on Borland, as it causes it to crash.\n";
 #else
-    if(std::numeric_limits<T>::has_infinity) {
+    if(boost::hash_detail::float_limits<T>::has_infinity) {
         T infinity = -log(zero);
         T infinity2 = (T) 1. / zero;
         T infinity3 = (T) -1. / minus_zero;
-        T infinity4 = std::numeric_limits<T>::infinity();
+        T infinity4 = boost::hash_detail::float_limits<T>::infinity();
 
         T minus_infinity = log(zero);
         T minus_infinity2 = (T) -1. / zero;
@@ -84,26 +84,26 @@ void float_tests(char const* name, T* = 0)
 
         // This should really be 'has_denorm == denorm_present' but some
         // compilers don't have 'denorm_present'. See also a later use.
-        if(std::numeric_limits<T>::has_denorm) {
+        if(boost::hash_detail::float_limits<T>::has_denorm) {
-            if(x1(std::numeric_limits<T>::denorm_min()) == x1(infinity)) {
+            if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(infinity)) {
                 std::cerr<<"x1(denorm_min) == x1(infinity) == "<<x1(infinity)<<"\n";
             }
-            if(x1(std::numeric_limits<T>::denorm_min()) == x1(minus_infinity)) {
+            if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(minus_infinity)) {
                 std::cerr<<"x1(denorm_min) == x1(-infinity) == "<<x1(minus_infinity)<<"\n";
             }
         }
-        if(std::numeric_limits<T>::has_quiet_NaN) {
+        if(boost::hash_detail::float_limits<T>::has_quiet_NaN) {
-            if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(infinity)) {
+            if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(infinity)) {
                 std::cerr<<"x1(quiet_NaN) == x1(infinity) == "<<x1(infinity)<<"\n";
             }
-            if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(minus_infinity)) {
+            if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(minus_infinity)) {
                 std::cerr<<"x1(quiet_NaN) == x1(-infinity) == "<<x1(minus_infinity)<<"\n";
             }
         }
     }
 #endif
 
-    T max = (std::numeric_limits<T>::max)();
+    T max = (boost::hash_detail::float_limits<T>::max)();
     T half_max = max / 2;
     T quarter_max = max / 4;
     T three_quarter_max = max - quarter_max;
@@ -132,50 +132,50 @@ void float_tests(char const* name, T* = 0)
     BOOST_TEST(x1(v1) == HASH_NAMESPACE::hash_value(v1));
     BOOST_TEST(x1(v2) == HASH_NAMESPACE::hash_value(v2));
 
-    BOOST_TEST(x1(std::numeric_limits<T>::epsilon()) ==
+    BOOST_TEST(x1(boost::hash_detail::float_limits<T>::epsilon()) ==
-            HASH_NAMESPACE::hash_value(std::numeric_limits<T>::epsilon()));
+            HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::epsilon()));
 
-    BOOST_TEST(std::numeric_limits<T>::epsilon() != (T) 0);
+    BOOST_TEST(boost::hash_detail::float_limits<T>::epsilon() != (T) 0);
-    if(x1(std::numeric_limits<T>::epsilon()) == x1((T) 0))
+    if(x1(boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 0))
         std::cerr<<"x1(epsilon) == x1(0) == "<<x1((T) 0)<<"\n";
 
-    BOOST_TEST(-std::numeric_limits<T>::epsilon() != (T) 0);
+    BOOST_TEST(-boost::hash_detail::float_limits<T>::epsilon() != (T) 0);
-    if(x1(-std::numeric_limits<T>::epsilon()) == x1((T) 0))
+    if(x1(-boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 0))
         std::cerr<<"x1(-epsilon) == x1(0) == "<<x1((T) 0)<<"\n";
 
-    BOOST_TEST((T) 1 + std::numeric_limits<T>::epsilon() != (T) 1);
+    BOOST_TEST((T) 1 + boost::hash_detail::float_limits<T>::epsilon() != (T) 1);
-    if(x1((T) 1 + std::numeric_limits<T>::epsilon()) == x1((T) 1))
+    if(x1((T) 1 + boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 1))
         std::cerr<<"x1(1 + epsilon) == x1(1) == "<<x1((T) 1)<<"\n";
 
-    BOOST_TEST((T) 1 - std::numeric_limits<T>::epsilon() != (T) 1);
+    BOOST_TEST((T) 1 - boost::hash_detail::float_limits<T>::epsilon() != (T) 1);
-    if(x1((T) 1 - std::numeric_limits<T>::epsilon()) == x1((T) 1))
+    if(x1((T) 1 - boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 1))
         std::cerr<<"x1(1 - epsilon) == x1(1) == "<<x1((T) 1)<<"\n";
 
-    BOOST_TEST((T) -1 + std::numeric_limits<T>::epsilon() != (T) -1);
+    BOOST_TEST((T) -1 + boost::hash_detail::float_limits<T>::epsilon() != (T) -1);
-    if(x1((T) -1 + std::numeric_limits<T>::epsilon()) == x1((T) -1))
+    if(x1((T) -1 + boost::hash_detail::float_limits<T>::epsilon()) == x1((T) -1))
         std::cerr<<"x1(-1 + epsilon) == x1(-1) == "<<x1((T) -1)<<"\n";
 
-    BOOST_TEST((T) -1 - std::numeric_limits<T>::epsilon() != (T) -1);
+    BOOST_TEST((T) -1 - boost::hash_detail::float_limits<T>::epsilon() != (T) -1);
-    if(x1((T) -1 - std::numeric_limits<T>::epsilon()) == x1((T) -1))
+    if(x1((T) -1 - boost::hash_detail::float_limits<T>::epsilon()) == x1((T) -1))
         std::cerr<<"x1(-1 - epsilon) == x1(-1) == "<<x1((T) -1)<<"\n";
 
     // As before.
-    if(std::numeric_limits<T>::has_denorm) {
+    if(boost::hash_detail::float_limits<T>::has_denorm) {
-        if(x1(std::numeric_limits<T>::denorm_min()) == x1(zero)) {
+        if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(zero)) {
             std::cerr<<"x1(denorm_min) == x1(zero) == "<<x1(zero)<<"\n";
         }
 #if !BOOST_WORKAROUND(__DECCXX_VER,<70190006)
         // The Tru64/CXX standard library prior to 7.1 contains a bug in the
-        // specialization of std::numeric_limits::denorm_min() for long
+        // specialization of boost::hash_detail::float_limits::denorm_min() for long
         // doubles which causes this test to fail.
-        if(x1(std::numeric_limits<T>::denorm_min()) !=
+        if(x1(boost::hash_detail::float_limits<T>::denorm_min()) !=
-            HASH_NAMESPACE::hash_value(std::numeric_limits<T>::denorm_min()))
+            HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::denorm_min()))
         {
-            std::cerr<<"x1(std::numeric_limits<T>::denorm_min()) = "
+            std::cerr<<"x1(boost::hash_detail::float_limits<T>::denorm_min()) = "
-                << x1(std::numeric_limits<T>::denorm_min())
+                << x1(boost::hash_detail::float_limits<T>::denorm_min())
-                << "\nhash_value(std::numeric_limits<T>::denorm_min()) = "
+                << "\nhash_value(boost::hash_detail::float_limits<T>::denorm_min()) = "
                 << HASH_NAMESPACE::hash_value(
-                        std::numeric_limits<T>::denorm_min())
+                        boost::hash_detail::float_limits<T>::denorm_min())
                 << "\nx1(0) = "<<x1(0)<<"\n";
         }
 #endif
@@ -183,12 +183,12 @@ void float_tests(char const* name, T* = 0)
 
 // NaN also causes borland to crash.
 #if !defined(__BORLANDC__)
-    if(std::numeric_limits<T>::has_quiet_NaN) {
+    if(boost::hash_detail::float_limits<T>::has_quiet_NaN) {
-        if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(1.0)) {
+        if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(1.0)) {
             std::cerr<<"x1(quiet_NaN) == x1(1.0) == "<<x1(1.0)<<"\n";
         }
-        BOOST_TEST(x1(std::numeric_limits<T>::quiet_NaN()) ==
+        BOOST_TEST(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) ==
-            HASH_NAMESPACE::hash_value(std::numeric_limits<T>::quiet_NaN()));
+            HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::quiet_NaN()));
     }
 #endif
 }

include/boost/functional/detail/hash_float.hpp

@@ -35,10 +35,61 @@
 #  endif
 #endif
 
+// On FreeBSD and OpenBSD, numeric_limits is not reliable for long doubles, but
+// the macros defined in <float.h> are. I don't know if this is also be the case for
+// other BSDs, but using the macros if they're available seems like the best
+// choice.
+
+#if defined(__FreeBSD__) || defined(__NetBSD__) && \
+    defined(__OpenBSD__) || defined(__DragonFly__)
+#include <float.h>
+#endif
+
 namespace boost
 {
     namespace hash_detail
     {
+        template <class T>
+        struct float_limits : std::numeric_limits<T> {};
+
+#if defined(__FreeBSD__) || defined(__NetBSD__) && \
+    defined(__OpenBSD__) || defined(__DragonFly__)
+        template <>
+        struct float_limits<long double>
+             : std::numeric_limits<long double>
+        {
+#if defined(LDBL_EPSILON)
+            static long double epsilon() {
+                return LDBL_EPSILON;
+            }
+#endif
+
+#if defined(LDBL_MANT_DIG)
+            BOOST_STATIC_CONSTANT(int, digits = LDBL_MANT_DIG);
+#endif
+
+#if defined(LDBL_MAX)
+            static long double (max)() {
+                return LDBL_MAX;
+            }
+#endif
+
+#if defined(LDBL_MIN)
+            static long double (min)() {
+                return LDBL_MIN;
+            }
+#endif
+
+#if defined(LDBL_MAX_EXP)
+            BOOST_STATIC_CONSTANT(int, max_exponent = LDBL_MAX_EXP);
+#endif
+
+#if defined(LDBL_MIN_EXP)
+            BOOST_STATIC_CONSTANT(int, min_exponent = LDBL_MIN_EXP);
+#endif
+        };
+#endif // __FreeBSD__/__NetBSD__/__OpenBSD__/__DragonFly__
+
         inline void hash_float_combine(std::size_t& seed, std::size_t value)
         {
             seed ^= value + (seed<<6) + (seed>>2);
@@ -63,19 +114,19 @@ namespace boost
             //BOOST_ASSERT(0 <= v && v < 0.5);
 
             v = boost::hash_detail::call_ldexp(v,
-                    std::numeric_limits<std::size_t>::digits + 1);
+                    float_limits<std::size_t>::digits + 1);
             std::size_t seed = static_cast<std::size_t>(v);
             v -= seed;
 
             // ceiling(digits(T) * log2(radix(T))/ digits(size_t)) - 1;
             std::size_t const length
-                = (std::numeric_limits<T>::digits *
+                = (float_limits<T>::digits *
-                        boost::static_log2<std::numeric_limits<T>::radix>::value - 1)
+                        boost::static_log2<float_limits<T>::radix>::value - 1)
-                / std::numeric_limits<std::size_t>::digits;
+                / float_limits<std::size_t>::digits;
 
             for(std::size_t i = 0; i < length; ++i)
             {
-                v = boost::hash_detail::call_ldexp(v, std::numeric_limits<std::size_t>::digits);
+                v = boost::hash_detail::call_ldexp(v, float_limits<std::size_t>::digits);
                 std::size_t part = static_cast<std::size_t>(v);
                 v -= part;
                 hash_float_combine(seed, part);