Simplify validity detection in SafeNumerics tests

base/numerics/safe_numerics_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
 #include <type_traits>
 
@@ skipping 45 matching lines @@
     return SrcLimits::max();
   Src max = SrcLimits::max() / 2 + (SrcLimits::is_integer ? 1 : 0);
   while (max != static_cast<Src>(static_cast<Dst>(max))) {
     max /= 2;
   }
   return static_cast<Dst>(max);
 }
 
 // Helper macros to wrap displaying the conversion types and line numbers.
 #define TEST_EXPECTED_VALIDITY(expected, actual)                           \
-  EXPECT_EQ(expected, CheckedNumeric<Dst>(actual).validity())              \
+  EXPECT_EQ(expected, CheckedNumeric<Dst>(actual).IsValid())               \

[brucedawson, 2016/05/20 21:00:57]

Now that expected has only two values it might make more sense to remove it and
have two simpler macros:

TEST_EXPECTED_SUCCESS and TEST_EXPECTED_FAILURE. I think this could make the
code and the output more readable.

[jschuh, 2016/05/20 21:19:05]

Done.

       << "Result test: Value " << +(actual).ValueUnsafe() << " as " << dst \
       << " on line " << line;
 
 #define TEST_EXPECTED_VALUE(expected, actual)                                \
   EXPECT_EQ(static_cast<Dst>(expected),                                      \
             CheckedNumeric<Dst>(actual).ValueUnsafe())                       \
       << "Result test: Value " << +((actual).ValueUnsafe()) << " as " << dst \
       << " on line " << line;
 
 // Signed integer arithmetic.
 template <typename Dst>
 static void TestSpecializedArithmetic(
     const char* dst,
     int line,
     typename std::enable_if<numeric_limits<Dst>::is_integer &&
                                 numeric_limits<Dst>::is_signed,
                             int>::type = 0) {
   typedef numeric_limits<Dst> DstLimits;
-  TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
-                         -CheckedNumeric<Dst>(DstLimits::min()));
-  TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()).Abs());
+  TEST_EXPECTED_VALIDITY(false, -CheckedNumeric<Dst>(DstLimits::min()));
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()).Abs());
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
 
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::max()) + -1);
-  TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) + -1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::max()) + -1);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) + -1);
   TEST_EXPECTED_VALIDITY(
-      RANGE_UNDERFLOW,
-      CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
+      false, CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
 
-  TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) - 1);
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()) - -1);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) - 1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()) - -1);
   TEST_EXPECTED_VALIDITY(
-      RANGE_OVERFLOW,
-      CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
+      false, CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
   TEST_EXPECTED_VALIDITY(
-      RANGE_UNDERFLOW,
-      CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
+      false, CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
 
-  TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) * 2);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) * 2);
 
-  TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) / -1);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) / -1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(-1) / 2);
 
   // Modulus is legal only for integers.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   TEST_EXPECTED_VALUE(-1, CheckedNumeric<Dst>(-1) % 2);
-  TEST_EXPECTED_VALIDITY(RANGE_INVALID, CheckedNumeric<Dst>(-1) % -2);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(-1) % -2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
   // Test all the different modulus combinations.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   CheckedNumeric<Dst> checked_dst = 1;
   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 }
 
 // Unsigned integer arithmetic.
 template <typename Dst>
 static void TestSpecializedArithmetic(
     const char* dst,
     int line,
     typename std::enable_if<numeric_limits<Dst>::is_integer &&
                                 !numeric_limits<Dst>::is_signed,
                             int>::type = 0) {
   typedef numeric_limits<Dst> DstLimits;
-  TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()).Abs());
-  TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) + -1);
-  TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW,
-                         CheckedNumeric<Dst>(DstLimits::min()) - 1);
+  TEST_EXPECTED_VALIDITY(true, -CheckedNumeric<Dst>(DstLimits::min()));
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()).Abs());
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) + -1);
+  TEST_EXPECTED_VALIDITY(false, CheckedNumeric<Dst>(DstLimits::min()) - 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) * 2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) / 2);
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
+  TEST_EXPECTED_VALIDITY(true,
                          CheckedNumeric<Dst>(DstLimits::min()).UnsignedAbs());
   TEST_EXPECTED_VALIDITY(
-      RANGE_VALID,
+      true,
       CheckedNumeric<typename SignedIntegerForSize<Dst>::type>(
           std::numeric_limits<typename SignedIntegerForSize<Dst>::type>::min())
           .UnsignedAbs());
 
   // Modulus is legal only for integers.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) % 2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::min()) % 2);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
   // Test all the different modulus combinations.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   CheckedNumeric<Dst> checked_dst = 1;
   TEST_EXPECTED_VALUE(0, checked_dst %= 1);
 }
 
 // Floating point arithmetic.
 template <typename Dst>
 void TestSpecializedArithmetic(
     const char* dst,
     int line,
     typename std::enable_if<numeric_limits<Dst>::is_iec559, int>::type = 0) {
   typedef numeric_limits<Dst> DstLimits;
-  TEST_EXPECTED_VALIDITY(RANGE_VALID, -CheckedNumeric<Dst>(DstLimits::min()));
+  TEST_EXPECTED_VALIDITY(true, -CheckedNumeric<Dst>(DstLimits::min()));
 
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()).Abs());
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()).Abs());
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
 
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()) + -1);
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::max()) + 1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()) + -1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::max()) + 1);
   TEST_EXPECTED_VALIDITY(
-      RANGE_UNDERFLOW,
-      CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
+      false, CheckedNumeric<Dst>(-DstLimits::max()) + -DstLimits::max());
 
   TEST_EXPECTED_VALIDITY(
-      RANGE_OVERFLOW,
-      CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
+      false, CheckedNumeric<Dst>(DstLimits::max()) - -DstLimits::max());
   TEST_EXPECTED_VALIDITY(
-      RANGE_UNDERFLOW,
-      CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
+      false, CheckedNumeric<Dst>(-DstLimits::max()) - DstLimits::max());
 
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()) * 2);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()) * 2);
 
   TEST_EXPECTED_VALUE(-0.5, CheckedNumeric<Dst>(-1.0) / 2);
   EXPECT_EQ(static_cast<Dst>(1.0), CheckedNumeric<Dst>(1.0).ValueFloating());
 }
 
 // Generic arithmetic tests.
 template <typename Dst>
 static void TestArithmetic(const char* dst, int line) {
   typedef numeric_limits<Dst> DstLimits;
 
@@ skipping 39 matching lines @@
   // Generic absolute value.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>().Abs());
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1).Abs());
   TEST_EXPECTED_VALUE(DstLimits::max(),
                       CheckedNumeric<Dst>(DstLimits::max()).Abs());
 
   // Generic addition.
   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>() + 1));
   TEST_EXPECTED_VALUE(2, (CheckedNumeric<Dst>(1) + 1));
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) + 1));
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::min()) + 1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::min()) + 1);
   TEST_EXPECTED_VALIDITY(
-      RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) + DstLimits::max());
+      false, CheckedNumeric<Dst>(DstLimits::max()) + DstLimits::max());
 
   // Generic subtraction.
   TEST_EXPECTED_VALUE(-1, (CheckedNumeric<Dst>() - 1));
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(1) - 1));
   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) - 1));
-  TEST_EXPECTED_VALIDITY(RANGE_VALID,
-                         CheckedNumeric<Dst>(DstLimits::max()) - 1);
+  TEST_EXPECTED_VALIDITY(true, CheckedNumeric<Dst>(DstLimits::max()) - 1);
 
   // Generic multiplication.
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>() * 1));
   TEST_EXPECTED_VALUE(1, (CheckedNumeric<Dst>(1) * 1));
   TEST_EXPECTED_VALUE(-2, (CheckedNumeric<Dst>(-1) * 2));
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * 0));
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(-1) * 0));
   TEST_EXPECTED_VALUE(0, (CheckedNumeric<Dst>(0) * -1));
   TEST_EXPECTED_VALIDITY(
-      RANGE_OVERFLOW, CheckedNumeric<Dst>(DstLimits::max()) * DstLimits::max());
+      false, CheckedNumeric<Dst>(DstLimits::max()) * DstLimits::max());
 
   // Generic division.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() / 1);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) / 1);
   TEST_EXPECTED_VALUE(DstLimits::min() / 2,
                       CheckedNumeric<Dst>(DstLimits::min()) / 2);
   TEST_EXPECTED_VALUE(DstLimits::max() / 2,
                       CheckedNumeric<Dst>(DstLimits::max()) / 2);
 
   TestSpecializedArithmetic<Dst>(dst, line);
@@ skipping 50 matching lines @@
                   // Not floating to integral and...
                   (!(DstLimits::is_integer && SrcLimits::is_iec559) &&
                    // Same sign, same numeric, source is narrower or same.
                    ((SrcLimits::is_signed == DstLimits::is_signed &&
                     sizeof(Dst) >= sizeof(Src)) ||
                    // Or signed destination and source is smaller
                     (DstLimits::is_signed && sizeof(Dst) > sizeof(Src)))),
                   "Comparison must be sign preserving and value preserving");
 
     const CheckedNumeric<Dst> checked_dst = SrcLimits::max();
-    TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst);
+    TEST_EXPECTED_VALIDITY(true, checked_dst);
     if (MaxExponent<Dst>::value > MaxExponent<Src>::value) {
       if (MaxExponent<Dst>::value >= MaxExponent<Src>::value * 2 - 1) {
         // At least twice larger type.
-        TEST_EXPECTED_VALIDITY(RANGE_VALID, SrcLimits::max() * checked_dst);
+        TEST_EXPECTED_VALIDITY(true, SrcLimits::max() * checked_dst);
 
       } else {  // Larger, but not at least twice as large.
-        TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, SrcLimits::max() * checked_dst);
-        TEST_EXPECTED_VALIDITY(RANGE_VALID, checked_dst + 1);
+        TEST_EXPECTED_VALIDITY(false, SrcLimits::max() * checked_dst);
+        TEST_EXPECTED_VALIDITY(true, checked_dst + 1);
       }
     } else {  // Same width type.
-      TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + 1);
+      TEST_EXPECTED_VALIDITY(false, checked_dst + 1);
     }
 
     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
     if (SrcLimits::is_iec559) {
       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max() * static_cast<Src>(-1));
       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
     } else if (numeric_limits<Src>::is_signed) {
       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
     }
   }
 };
 
 template <typename Dst, typename Src>
 struct TestNumericConversion<Dst, Src, SIGN_PRESERVING_NARROW> {
   static void Test(const char *dst, const char *src, int line) {
     typedef numeric_limits<Src> SrcLimits;
     typedef numeric_limits<Dst> DstLimits;
     static_assert(SrcLimits::is_signed == DstLimits::is_signed,
                   "Destination and source sign must be the same");
     static_assert(sizeof(Dst) < sizeof(Src) ||
                    (DstLimits::is_integer && SrcLimits::is_iec559),
                   "Destination must be narrower than source");
 
     const CheckedNumeric<Dst> checked_dst;
-    TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst + SrcLimits::max());
     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
-    TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst - SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst - SrcLimits::max());
 
     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
     if (SrcLimits::is_iec559) {
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
       if (DstLimits::is_integer) {
         if (SrcLimits::digits < DstLimits::digits) {
           TEST_EXPECTED_RANGE(RANGE_OVERFLOW,
                               static_cast<Src>(DstLimits::max()));
         } else {
           TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(DstLimits::max()));
         }
         TEST_EXPECTED_RANGE(
             RANGE_VALID,
             static_cast<Src>(GetMaxConvertibleToFloat<Src, Dst>()));
         TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(DstLimits::min()));
       }
     } else if (SrcLimits::is_signed) {
       TEST_EXPECTED_VALUE(-1, checked_dst - static_cast<Src>(1));
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
       TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(-1));
     } else {
-      TEST_EXPECTED_VALIDITY(RANGE_INVALID, checked_dst - static_cast<Src>(1));
+      TEST_EXPECTED_VALIDITY(false, checked_dst - static_cast<Src>(1));
       TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
     }
   }
 };
 
 template <typename Dst, typename Src>
 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_WIDEN_OR_EQUAL> {
   static void Test(const char *dst, const char *src, int line) {
     typedef numeric_limits<Src> SrcLimits;
     typedef numeric_limits<Dst> DstLimits;
     static_assert(sizeof(Dst) >= sizeof(Src),
                   "Destination must be equal or wider than source.");
     static_assert(SrcLimits::is_signed, "Source must be signed");
     static_assert(!DstLimits::is_signed, "Destination must be unsigned");
 
     const CheckedNumeric<Dst> checked_dst;
     TEST_EXPECTED_VALUE(SrcLimits::max(), checked_dst + SrcLimits::max());
-    TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
-    TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst + static_cast<Src>(-1));
+    TEST_EXPECTED_VALIDITY(false, checked_dst + -SrcLimits::max());
 
     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::min());
     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::max());
     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
   }
 };
 
 template <typename Dst, typename Src>
 struct TestNumericConversion<Dst, Src, SIGN_TO_UNSIGN_NARROW> {
   static void Test(const char *dst, const char *src, int line) {
     typedef numeric_limits<Src> SrcLimits;
     typedef numeric_limits<Dst> DstLimits;
     static_assert((DstLimits::is_integer && SrcLimits::is_iec559) ||
                    (sizeof(Dst) < sizeof(Src)),
                   "Destination must be narrower than source.");
     static_assert(SrcLimits::is_signed, "Source must be signed.");
     static_assert(!DstLimits::is_signed, "Destination must be unsigned.");
 
     const CheckedNumeric<Dst> checked_dst;
     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
-    TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
-    TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + static_cast<Src>(-1));
-    TEST_EXPECTED_VALIDITY(RANGE_UNDERFLOW, checked_dst + -SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst + SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst + static_cast<Src>(-1));
+    TEST_EXPECTED_VALIDITY(false, checked_dst + -SrcLimits::max());
 
     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
     TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, static_cast<Src>(-1));
     if (SrcLimits::is_iec559) {
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::max() * -1);
       TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::infinity());
       TEST_EXPECTED_RANGE(RANGE_UNDERFLOW, SrcLimits::infinity() * -1);
       TEST_EXPECTED_RANGE(RANGE_INVALID, SrcLimits::quiet_NaN());
       if (DstLimits::is_integer) {
@@ skipping 19 matching lines @@
   static void Test(const char *dst, const char *src, int line) {
     typedef numeric_limits<Src> SrcLimits;
     typedef numeric_limits<Dst> DstLimits;
     static_assert(sizeof(Dst) <= sizeof(Src),
                   "Destination must be narrower or equal to source.");
     static_assert(!SrcLimits::is_signed, "Source must be unsigned.");
     static_assert(DstLimits::is_signed, "Destination must be signed.");
 
     const CheckedNumeric<Dst> checked_dst;
     TEST_EXPECTED_VALUE(1, checked_dst + static_cast<Src>(1));
-    TEST_EXPECTED_VALIDITY(RANGE_OVERFLOW, checked_dst + SrcLimits::max());
+    TEST_EXPECTED_VALIDITY(false, checked_dst + SrcLimits::max());
     TEST_EXPECTED_VALUE(SrcLimits::min(), checked_dst + SrcLimits::min());
 
     TEST_EXPECTED_RANGE(RANGE_VALID, SrcLimits::min());
     TEST_EXPECTED_RANGE(RANGE_OVERFLOW, SrcLimits::max());
     TEST_EXPECTED_RANGE(RANGE_VALID, static_cast<Src>(1));
   }
 };
 
 // Helper macro to wrap displaying the conversion types and line numbers
 #define TEST_NUMERIC_CONVERSION(d, s, t) \
@@ skipping 260 matching lines @@
 
   CheckedNumeric<int> too_large = std::numeric_limits<int>::max();
   EXPECT_TRUE(too_large.IsValid());
   too_large += d;
   EXPECT_FALSE(too_large.IsValid());
   too_large -= d;
   EXPECT_FALSE(too_large.IsValid());
   too_large /= d;
   EXPECT_FALSE(too_large.IsValid());
 }