Add test set

Author: mborland

include/boost/decimal/cmath.hpp

@@ -53,6 +53,7 @@
 #include <boost/decimal/detail/cmath/tgamma.hpp>
 #include <boost/decimal/detail/cmath/trunc.hpp>
 #include <boost/decimal/detail/cmath/nan.hpp>
+#include <boost/decimal/detail/cmath/logb.hpp>
 #include <boost/decimal/numbers.hpp>
 
 // Macros from 3.6.2

include/boost/decimal/decimal32.hpp

@@ -165,6 +165,9 @@ class decimal32 final // NOLINT(cppcoreguidelines-special-member-functions,hicpp
     template <typename T>
     friend constexpr auto ilogb(T d) noexcept -> std::enable_if_t<detail::is_decimal_floating_point_v<T>, int>;
 
+    template <typename T>
+    friend constexpr auto logb(T num) noexcept -> std::enable_if_t<detail::is_decimal_floating_point_v<T>, T>;
+
     // Debug bit pattern
     friend constexpr auto from_bits(std::uint32_t bits) noexcept -> decimal32;
     friend BOOST_DECIMAL_CXX20_CONSTEXPR auto to_bits(decimal32 rhs) noexcept -> std::uint32_t;

include/boost/decimal/decimal64.hpp

@@ -208,6 +208,9 @@ class decimal64 final
     template <typename T>
     friend constexpr auto ilogb(T d) noexcept -> std::enable_if_t<detail::is_decimal_floating_point_v<T>, int>;
 
+    template <typename T>
+    friend constexpr auto logb(T num) noexcept -> std::enable_if_t<detail::is_decimal_floating_point_v<T>, T>;
+
 public:
     // 3.2.3.1 construct/copy/destroy
     constexpr decimal64() noexcept = default;

test/test_cmath.cpp

@@ -610,12 +610,41 @@ void test_ilogb()
         BOOST_TEST_EQ(ilogb(Dec(1, 0)), 398);
         BOOST_TEST_EQ(ilogb(Dec(10, 0)), 399);
     }
+    else
+    {
+        BOOST_TEST_EQ(ilogb(Dec(1, 0)), 6176);
+        BOOST_TEST_EQ(ilogb(Dec(10, 0)), 6177);
+    }
 
     BOOST_TEST_EQ(ilogb(Dec(0)), FP_ILOGB0);
     BOOST_TEST_EQ(ilogb(std::numeric_limits<Dec>::infinity()), INT_MAX);
     BOOST_TEST_EQ(ilogb(std::numeric_limits<Dec>::quiet_NaN()), FP_ILOGBNAN);
 }
 
+template <typename Dec>
+void test_logb()
+{
+    BOOST_DECIMAL_IF_CONSTEXPR (std::is_same<Dec, decimal32>::value)
+    {
+        BOOST_TEST_EQ(ilogb(Dec(1, 0)), Dec(101));
+        BOOST_TEST_EQ(ilogb(Dec(10, 0)), Dec(102));
+    }
+    else BOOST_DECIMAL_IF_CONSTEXPR (std::is_same<Dec, decimal64>::value)
+    {
+        BOOST_TEST_EQ(ilogb(Dec(1, 0)), Dec(398));
+        BOOST_TEST_EQ(ilogb(Dec(10, 0)), Dec(399));
+    }
+    else
+    {
+        BOOST_TEST_EQ(ilogb(Dec(1, 0)), 6176);
+        BOOST_TEST_EQ(ilogb(Dec(10, 0)), 6177);
+    }
+
+    BOOST_TEST_EQ(logb(Dec(0)), -std::numeric_limits<Dec>::infinity());
+    BOOST_TEST_EQ(logb(std::numeric_limits<Dec>::infinity()), std::numeric_limits<Dec>::infinity());
+    BOOST_TEST(isnan(logb(std::numeric_limits<Dec>::quiet_NaN())));
+}
+
 template <typename Dec>
 void test_sqrt()
 {
@@ -1422,6 +1451,11 @@ int main()
 
     test_ilogb<decimal32>();
     test_ilogb<decimal64>();
+    test_ilogb<decimal128>();
+
+    test_logb<decimal32>();
+    test_logb<decimal64>();
+    test_logb<decimal128>();
 
     test_sqrt<decimal32>();
     test_sqrt<decimal64>();