Make safe_cmp::* constexpr

Because it's easy and generally useful, and because a later CL in this
series needs it.

BUG=webrtc:7459

Review-Url: https://codereview.webrtc.org/2808603002
Cr-Commit-Position: refs/heads/master@{#17633}
diff --git a/webrtc/base/safe_compare.h b/webrtc/base/safe_compare.h
index 494a0c1..0350d5d 100644
--- a/webrtc/base/safe_compare.h
+++ b/webrtc/base/safe_compare.h
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-// This file defines six functions:
+// This file defines six constexpr functions:
 //
 //   rtc::safe_cmp::Eq  // ==
 //   rtc::safe_cmp::Ne  // !=
@@ -70,7 +70,7 @@
                         : 0> {};
 
 template <typename T>
-inline typename std::make_unsigned<T>::type MakeUnsigned(T a) {
+constexpr typename std::make_unsigned<T>::type MakeUnsigned(T a) {
   return static_cast<typename std::make_unsigned<T>::type>(a);
 }
 
@@ -80,7 +80,7 @@
           typename T2,
           typename std::enable_if<std::is_signed<T1>::value ==
                                   std::is_signed<T2>::value>::type* = nullptr>
-inline bool Cmp(T1 a, T2 b) {
+constexpr bool Cmp(T1 a, T2 b) {
   return Op::Op(a, b);
 }
 
@@ -92,7 +92,7 @@
           typename std::enable_if<std::is_signed<T1>::value &&
                                   std::is_unsigned<T2>::value &&
                                   LargerInt<T2, T1>::value>::type* = nullptr>
-inline bool Cmp(T1 a, T2 b) {
+constexpr bool Cmp(T1 a, T2 b) {
   return Op::Op(a, static_cast<typename LargerInt<T2, T1>::type>(b));
 }
 
@@ -104,7 +104,7 @@
           typename std::enable_if<std::is_unsigned<T1>::value &&
                                   std::is_signed<T2>::value &&
                                   LargerInt<T1, T2>::value>::type* = nullptr>
-inline bool Cmp(T1 a, T2 b) {
+constexpr bool Cmp(T1 a, T2 b) {
   return Op::Op(static_cast<typename LargerInt<T1, T2>::type>(a), b);
 }
 
@@ -116,7 +116,7 @@
           typename std::enable_if<std::is_signed<T1>::value &&
                                   std::is_unsigned<T2>::value &&
                                   !LargerInt<T2, T1>::value>::type* = nullptr>
-inline bool Cmp(T1 a, T2 b) {
+constexpr bool Cmp(T1 a, T2 b) {
   return a < 0 ? Op::Op(-1, 0) : Op::Op(safe_cmp_impl::MakeUnsigned(a), b);
 }
 
@@ -128,7 +128,7 @@
           typename std::enable_if<std::is_unsigned<T1>::value &&
                                   std::is_signed<T2>::value &&
                                   !LargerInt<T1, T2>::value>::type* = nullptr>
-inline bool Cmp(T1 a, T2 b) {
+constexpr bool Cmp(T1 a, T2 b) {
   return b < 0 ? Op::Op(0, -1) : Op::Op(a, safe_cmp_impl::MakeUnsigned(b));
 }
 
@@ -149,19 +149,21 @@
 
 }  // namespace safe_cmp_impl
 
-#define RTC_SAFECMP_MAKE_FUN(name)                                           \
-  template <typename T1, typename T2,                                        \
-            typename std::enable_if<IsIntlike<T1>::value &&                  \
-                                    IsIntlike<T2>::value>::type* = nullptr>  \
-  inline bool name(T1 a, T2 b) {                                             \
-    /* Unary plus here turns enums into real integral types. */              \
-    return safe_cmp_impl::Cmp<safe_cmp_impl::name##Op>(+a, +b);              \
-  }                                                                          \
-  template <typename T1, typename T2,                                        \
-            typename std::enable_if<!IsIntlike<T1>::value ||                 \
-                                    !IsIntlike<T2>::value>::type* = nullptr> \
-  inline bool name(T1&& a, T2&& b) {                                         \
-    return safe_cmp_impl::name##Op::Op(a, b);                                \
+#define RTC_SAFECMP_MAKE_FUN(name)                                            \
+  template <typename T1, typename T2>                                         \
+  constexpr                                                                   \
+      typename std::enable_if<IsIntlike<T1>::value && IsIntlike<T2>::value,   \
+                              bool>::type                                     \
+      name(T1 a, T2 b) {                                                      \
+    /* Unary plus here turns enums into real integral types. */               \
+    return safe_cmp_impl::Cmp<safe_cmp_impl::name##Op>(+a, +b);               \
+  }                                                                           \
+  template <typename T1, typename T2>                                         \
+  constexpr                                                                   \
+      typename std::enable_if<!IsIntlike<T1>::value || !IsIntlike<T2>::value, \
+                              bool>::type                                     \
+      name(const T1& a, const T2& b) {                                        \
+    return safe_cmp_impl::name##Op::Op(a, b);                                 \
   }
 RTC_SAFECMP_MAKE_FUN(Eq)
 RTC_SAFECMP_MAKE_FUN(Ne)
diff --git a/webrtc/base/safe_compare_unittest.cc b/webrtc/base/safe_compare_unittest.cc
index f52c7ee..9663164 100644
--- a/webrtc/base/safe_compare_unittest.cc
+++ b/webrtc/base/safe_compare_unittest.cc
@@ -26,8 +26,8 @@
 static_assert(static_cast<std::uintmax_t>(m1) == umax, "");
 static_assert(m1 == static_cast<std::intmax_t>(umax), "");
 
-std::pair<int, int> p1(1, 1);
-std::pair<int, int> p2(1, 2);
+static const std::pair<int, int> p1(1, 1);
+static const std::pair<int, int> p2(1, 2);
 
 }  // namespace
 
@@ -77,48 +77,48 @@
 // clang-format on
 
 TEST(SafeCmpTest, Eq) {
-  EXPECT_FALSE(safe_cmp::Eq(-1, 2));
-  EXPECT_FALSE(safe_cmp::Eq(-1, 2u));
-  EXPECT_FALSE(safe_cmp::Eq(2, -1));
-  EXPECT_FALSE(safe_cmp::Eq(2u, -1));
+  static_assert(!safe_cmp::Eq(-1, 2), "");
+  static_assert(!safe_cmp::Eq(-1, 2u), "");
+  static_assert(!safe_cmp::Eq(2, -1), "");
+  static_assert(!safe_cmp::Eq(2u, -1), "");
 
-  EXPECT_FALSE(safe_cmp::Eq(1, 2));
-  EXPECT_FALSE(safe_cmp::Eq(1, 2u));
-  EXPECT_FALSE(safe_cmp::Eq(1u, 2));
-  EXPECT_FALSE(safe_cmp::Eq(1u, 2u));
-  EXPECT_FALSE(safe_cmp::Eq(2, 1));
-  EXPECT_FALSE(safe_cmp::Eq(2, 1u));
-  EXPECT_FALSE(safe_cmp::Eq(2u, 1));
-  EXPECT_FALSE(safe_cmp::Eq(2u, 1u));
+  static_assert(!safe_cmp::Eq(1, 2), "");
+  static_assert(!safe_cmp::Eq(1, 2u), "");
+  static_assert(!safe_cmp::Eq(1u, 2), "");
+  static_assert(!safe_cmp::Eq(1u, 2u), "");
+  static_assert(!safe_cmp::Eq(2, 1), "");
+  static_assert(!safe_cmp::Eq(2, 1u), "");
+  static_assert(!safe_cmp::Eq(2u, 1), "");
+  static_assert(!safe_cmp::Eq(2u, 1u), "");
 
-  EXPECT_TRUE(safe_cmp::Eq(2, 2));
-  EXPECT_TRUE(safe_cmp::Eq(2, 2u));
-  EXPECT_TRUE(safe_cmp::Eq(2u, 2));
-  EXPECT_TRUE(safe_cmp::Eq(2u, 2u));
+  static_assert(safe_cmp::Eq(2, 2), "");
+  static_assert(safe_cmp::Eq(2, 2u), "");
+  static_assert(safe_cmp::Eq(2u, 2), "");
+  static_assert(safe_cmp::Eq(2u, 2u), "");
 
-  EXPECT_TRUE(safe_cmp::Eq(imin, imin));
-  EXPECT_FALSE(safe_cmp::Eq(imin, umax));
-  EXPECT_FALSE(safe_cmp::Eq(umax, imin));
-  EXPECT_TRUE(safe_cmp::Eq(umax, umax));
+  static_assert(safe_cmp::Eq(imin, imin), "");
+  static_assert(!safe_cmp::Eq(imin, umax), "");
+  static_assert(!safe_cmp::Eq(umax, imin), "");
+  static_assert(safe_cmp::Eq(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Eq(m1, m1));
-  EXPECT_FALSE(safe_cmp::Eq(m1, umax));
-  EXPECT_FALSE(safe_cmp::Eq(umax, m1));
-  EXPECT_TRUE(safe_cmp::Eq(umax, umax));
+  static_assert(safe_cmp::Eq(m1, m1), "");
+  static_assert(!safe_cmp::Eq(m1, umax), "");
+  static_assert(!safe_cmp::Eq(umax, m1), "");
+  static_assert(safe_cmp::Eq(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Eq(1, 2));
-  EXPECT_FALSE(safe_cmp::Eq(1, 2.0));
-  EXPECT_FALSE(safe_cmp::Eq(1.0, 2));
-  EXPECT_FALSE(safe_cmp::Eq(1.0, 2.0));
-  EXPECT_FALSE(safe_cmp::Eq(2, 1));
-  EXPECT_FALSE(safe_cmp::Eq(2, 1.0));
-  EXPECT_FALSE(safe_cmp::Eq(2.0, 1));
-  EXPECT_FALSE(safe_cmp::Eq(2.0, 1.0));
+  static_assert(!safe_cmp::Eq(1, 2), "");
+  static_assert(!safe_cmp::Eq(1, 2.0), "");
+  static_assert(!safe_cmp::Eq(1.0, 2), "");
+  static_assert(!safe_cmp::Eq(1.0, 2.0), "");
+  static_assert(!safe_cmp::Eq(2, 1), "");
+  static_assert(!safe_cmp::Eq(2, 1.0), "");
+  static_assert(!safe_cmp::Eq(2.0, 1), "");
+  static_assert(!safe_cmp::Eq(2.0, 1.0), "");
 
-  EXPECT_TRUE(safe_cmp::Eq(2, 2));
-  EXPECT_TRUE(safe_cmp::Eq(2, 2.0));
-  EXPECT_TRUE(safe_cmp::Eq(2.0, 2));
-  EXPECT_TRUE(safe_cmp::Eq(2.0, 2.0));
+  static_assert(safe_cmp::Eq(2, 2), "");
+  static_assert(safe_cmp::Eq(2, 2.0), "");
+  static_assert(safe_cmp::Eq(2.0, 2), "");
+  static_assert(safe_cmp::Eq(2.0, 2.0), "");
 
   EXPECT_TRUE(safe_cmp::Eq(p1, p1));
   EXPECT_FALSE(safe_cmp::Eq(p1, p2));
@@ -127,48 +127,48 @@
 }
 
 TEST(SafeCmpTest, Ne) {
-  EXPECT_TRUE(safe_cmp::Ne(-1, 2));
-  EXPECT_TRUE(safe_cmp::Ne(-1, 2u));
-  EXPECT_TRUE(safe_cmp::Ne(2, -1));
-  EXPECT_TRUE(safe_cmp::Ne(2u, -1));
+  static_assert(safe_cmp::Ne(-1, 2), "");
+  static_assert(safe_cmp::Ne(-1, 2u), "");
+  static_assert(safe_cmp::Ne(2, -1), "");
+  static_assert(safe_cmp::Ne(2u, -1), "");
 
-  EXPECT_TRUE(safe_cmp::Ne(1, 2));
-  EXPECT_TRUE(safe_cmp::Ne(1, 2u));
-  EXPECT_TRUE(safe_cmp::Ne(1u, 2));
-  EXPECT_TRUE(safe_cmp::Ne(1u, 2u));
-  EXPECT_TRUE(safe_cmp::Ne(2, 1));
-  EXPECT_TRUE(safe_cmp::Ne(2, 1u));
-  EXPECT_TRUE(safe_cmp::Ne(2u, 1));
-  EXPECT_TRUE(safe_cmp::Ne(2u, 1u));
+  static_assert(safe_cmp::Ne(1, 2), "");
+  static_assert(safe_cmp::Ne(1, 2u), "");
+  static_assert(safe_cmp::Ne(1u, 2), "");
+  static_assert(safe_cmp::Ne(1u, 2u), "");
+  static_assert(safe_cmp::Ne(2, 1), "");
+  static_assert(safe_cmp::Ne(2, 1u), "");
+  static_assert(safe_cmp::Ne(2u, 1), "");
+  static_assert(safe_cmp::Ne(2u, 1u), "");
 
-  EXPECT_FALSE(safe_cmp::Ne(2, 2));
-  EXPECT_FALSE(safe_cmp::Ne(2, 2u));
-  EXPECT_FALSE(safe_cmp::Ne(2u, 2));
-  EXPECT_FALSE(safe_cmp::Ne(2u, 2u));
+  static_assert(!safe_cmp::Ne(2, 2), "");
+  static_assert(!safe_cmp::Ne(2, 2u), "");
+  static_assert(!safe_cmp::Ne(2u, 2), "");
+  static_assert(!safe_cmp::Ne(2u, 2u), "");
 
-  EXPECT_FALSE(safe_cmp::Ne(imin, imin));
-  EXPECT_TRUE(safe_cmp::Ne(imin, umax));
-  EXPECT_TRUE(safe_cmp::Ne(umax, imin));
-  EXPECT_FALSE(safe_cmp::Ne(umax, umax));
+  static_assert(!safe_cmp::Ne(imin, imin), "");
+  static_assert(safe_cmp::Ne(imin, umax), "");
+  static_assert(safe_cmp::Ne(umax, imin), "");
+  static_assert(!safe_cmp::Ne(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Ne(m1, m1));
-  EXPECT_TRUE(safe_cmp::Ne(m1, umax));
-  EXPECT_TRUE(safe_cmp::Ne(umax, m1));
-  EXPECT_FALSE(safe_cmp::Ne(umax, umax));
+  static_assert(!safe_cmp::Ne(m1, m1), "");
+  static_assert(safe_cmp::Ne(m1, umax), "");
+  static_assert(safe_cmp::Ne(umax, m1), "");
+  static_assert(!safe_cmp::Ne(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Ne(1, 2));
-  EXPECT_TRUE(safe_cmp::Ne(1, 2.0));
-  EXPECT_TRUE(safe_cmp::Ne(1.0, 2));
-  EXPECT_TRUE(safe_cmp::Ne(1.0, 2.0));
-  EXPECT_TRUE(safe_cmp::Ne(2, 1));
-  EXPECT_TRUE(safe_cmp::Ne(2, 1.0));
-  EXPECT_TRUE(safe_cmp::Ne(2.0, 1));
-  EXPECT_TRUE(safe_cmp::Ne(2.0, 1.0));
+  static_assert(safe_cmp::Ne(1, 2), "");
+  static_assert(safe_cmp::Ne(1, 2.0), "");
+  static_assert(safe_cmp::Ne(1.0, 2), "");
+  static_assert(safe_cmp::Ne(1.0, 2.0), "");
+  static_assert(safe_cmp::Ne(2, 1), "");
+  static_assert(safe_cmp::Ne(2, 1.0), "");
+  static_assert(safe_cmp::Ne(2.0, 1), "");
+  static_assert(safe_cmp::Ne(2.0, 1.0), "");
 
-  EXPECT_FALSE(safe_cmp::Ne(2, 2));
-  EXPECT_FALSE(safe_cmp::Ne(2, 2.0));
-  EXPECT_FALSE(safe_cmp::Ne(2.0, 2));
-  EXPECT_FALSE(safe_cmp::Ne(2.0, 2.0));
+  static_assert(!safe_cmp::Ne(2, 2), "");
+  static_assert(!safe_cmp::Ne(2, 2.0), "");
+  static_assert(!safe_cmp::Ne(2.0, 2), "");
+  static_assert(!safe_cmp::Ne(2.0, 2.0), "");
 
   EXPECT_FALSE(safe_cmp::Ne(p1, p1));
   EXPECT_TRUE(safe_cmp::Ne(p1, p2));
@@ -177,48 +177,48 @@
 }
 
 TEST(SafeCmpTest, Lt) {
-  EXPECT_TRUE(safe_cmp::Lt(-1, 2));
-  EXPECT_TRUE(safe_cmp::Lt(-1, 2u));
-  EXPECT_FALSE(safe_cmp::Lt(2, -1));
-  EXPECT_FALSE(safe_cmp::Lt(2u, -1));
+  static_assert(safe_cmp::Lt(-1, 2), "");
+  static_assert(safe_cmp::Lt(-1, 2u), "");
+  static_assert(!safe_cmp::Lt(2, -1), "");
+  static_assert(!safe_cmp::Lt(2u, -1), "");
 
-  EXPECT_TRUE(safe_cmp::Lt(1, 2));
-  EXPECT_TRUE(safe_cmp::Lt(1, 2u));
-  EXPECT_TRUE(safe_cmp::Lt(1u, 2));
-  EXPECT_TRUE(safe_cmp::Lt(1u, 2u));
-  EXPECT_FALSE(safe_cmp::Lt(2, 1));
-  EXPECT_FALSE(safe_cmp::Lt(2, 1u));
-  EXPECT_FALSE(safe_cmp::Lt(2u, 1));
-  EXPECT_FALSE(safe_cmp::Lt(2u, 1u));
+  static_assert(safe_cmp::Lt(1, 2), "");
+  static_assert(safe_cmp::Lt(1, 2u), "");
+  static_assert(safe_cmp::Lt(1u, 2), "");
+  static_assert(safe_cmp::Lt(1u, 2u), "");
+  static_assert(!safe_cmp::Lt(2, 1), "");
+  static_assert(!safe_cmp::Lt(2, 1u), "");
+  static_assert(!safe_cmp::Lt(2u, 1), "");
+  static_assert(!safe_cmp::Lt(2u, 1u), "");
 
-  EXPECT_FALSE(safe_cmp::Lt(2, 2));
-  EXPECT_FALSE(safe_cmp::Lt(2, 2u));
-  EXPECT_FALSE(safe_cmp::Lt(2u, 2));
-  EXPECT_FALSE(safe_cmp::Lt(2u, 2u));
+  static_assert(!safe_cmp::Lt(2, 2), "");
+  static_assert(!safe_cmp::Lt(2, 2u), "");
+  static_assert(!safe_cmp::Lt(2u, 2), "");
+  static_assert(!safe_cmp::Lt(2u, 2u), "");
 
-  EXPECT_FALSE(safe_cmp::Lt(imin, imin));
-  EXPECT_TRUE(safe_cmp::Lt(imin, umax));
-  EXPECT_FALSE(safe_cmp::Lt(umax, imin));
-  EXPECT_FALSE(safe_cmp::Lt(umax, umax));
+  static_assert(!safe_cmp::Lt(imin, imin), "");
+  static_assert(safe_cmp::Lt(imin, umax), "");
+  static_assert(!safe_cmp::Lt(umax, imin), "");
+  static_assert(!safe_cmp::Lt(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Lt(m1, m1));
-  EXPECT_TRUE(safe_cmp::Lt(m1, umax));
-  EXPECT_FALSE(safe_cmp::Lt(umax, m1));
-  EXPECT_FALSE(safe_cmp::Lt(umax, umax));
+  static_assert(!safe_cmp::Lt(m1, m1), "");
+  static_assert(safe_cmp::Lt(m1, umax), "");
+  static_assert(!safe_cmp::Lt(umax, m1), "");
+  static_assert(!safe_cmp::Lt(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Lt(1, 2));
-  EXPECT_TRUE(safe_cmp::Lt(1, 2.0));
-  EXPECT_TRUE(safe_cmp::Lt(1.0, 2));
-  EXPECT_TRUE(safe_cmp::Lt(1.0, 2.0));
-  EXPECT_FALSE(safe_cmp::Lt(2, 1));
-  EXPECT_FALSE(safe_cmp::Lt(2, 1.0));
-  EXPECT_FALSE(safe_cmp::Lt(2.0, 1));
-  EXPECT_FALSE(safe_cmp::Lt(2.0, 1.0));
+  static_assert(safe_cmp::Lt(1, 2), "");
+  static_assert(safe_cmp::Lt(1, 2.0), "");
+  static_assert(safe_cmp::Lt(1.0, 2), "");
+  static_assert(safe_cmp::Lt(1.0, 2.0), "");
+  static_assert(!safe_cmp::Lt(2, 1), "");
+  static_assert(!safe_cmp::Lt(2, 1.0), "");
+  static_assert(!safe_cmp::Lt(2.0, 1), "");
+  static_assert(!safe_cmp::Lt(2.0, 1.0), "");
 
-  EXPECT_FALSE(safe_cmp::Lt(2, 2));
-  EXPECT_FALSE(safe_cmp::Lt(2, 2.0));
-  EXPECT_FALSE(safe_cmp::Lt(2.0, 2));
-  EXPECT_FALSE(safe_cmp::Lt(2.0, 2.0));
+  static_assert(!safe_cmp::Lt(2, 2), "");
+  static_assert(!safe_cmp::Lt(2, 2.0), "");
+  static_assert(!safe_cmp::Lt(2.0, 2), "");
+  static_assert(!safe_cmp::Lt(2.0, 2.0), "");
 
   EXPECT_FALSE(safe_cmp::Lt(p1, p1));
   EXPECT_TRUE(safe_cmp::Lt(p1, p2));
@@ -227,48 +227,48 @@
 }
 
 TEST(SafeCmpTest, Le) {
-  EXPECT_TRUE(safe_cmp::Le(-1, 2));
-  EXPECT_TRUE(safe_cmp::Le(-1, 2u));
-  EXPECT_FALSE(safe_cmp::Le(2, -1));
-  EXPECT_FALSE(safe_cmp::Le(2u, -1));
+  static_assert(safe_cmp::Le(-1, 2), "");
+  static_assert(safe_cmp::Le(-1, 2u), "");
+  static_assert(!safe_cmp::Le(2, -1), "");
+  static_assert(!safe_cmp::Le(2u, -1), "");
 
-  EXPECT_TRUE(safe_cmp::Le(1, 2));
-  EXPECT_TRUE(safe_cmp::Le(1, 2u));
-  EXPECT_TRUE(safe_cmp::Le(1u, 2));
-  EXPECT_TRUE(safe_cmp::Le(1u, 2u));
-  EXPECT_FALSE(safe_cmp::Le(2, 1));
-  EXPECT_FALSE(safe_cmp::Le(2, 1u));
-  EXPECT_FALSE(safe_cmp::Le(2u, 1));
-  EXPECT_FALSE(safe_cmp::Le(2u, 1u));
+  static_assert(safe_cmp::Le(1, 2), "");
+  static_assert(safe_cmp::Le(1, 2u), "");
+  static_assert(safe_cmp::Le(1u, 2), "");
+  static_assert(safe_cmp::Le(1u, 2u), "");
+  static_assert(!safe_cmp::Le(2, 1), "");
+  static_assert(!safe_cmp::Le(2, 1u), "");
+  static_assert(!safe_cmp::Le(2u, 1), "");
+  static_assert(!safe_cmp::Le(2u, 1u), "");
 
-  EXPECT_TRUE(safe_cmp::Le(2, 2));
-  EXPECT_TRUE(safe_cmp::Le(2, 2u));
-  EXPECT_TRUE(safe_cmp::Le(2u, 2));
-  EXPECT_TRUE(safe_cmp::Le(2u, 2u));
+  static_assert(safe_cmp::Le(2, 2), "");
+  static_assert(safe_cmp::Le(2, 2u), "");
+  static_assert(safe_cmp::Le(2u, 2), "");
+  static_assert(safe_cmp::Le(2u, 2u), "");
 
-  EXPECT_TRUE(safe_cmp::Le(imin, imin));
-  EXPECT_TRUE(safe_cmp::Le(imin, umax));
-  EXPECT_FALSE(safe_cmp::Le(umax, imin));
-  EXPECT_TRUE(safe_cmp::Le(umax, umax));
+  static_assert(safe_cmp::Le(imin, imin), "");
+  static_assert(safe_cmp::Le(imin, umax), "");
+  static_assert(!safe_cmp::Le(umax, imin), "");
+  static_assert(safe_cmp::Le(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Le(m1, m1));
-  EXPECT_TRUE(safe_cmp::Le(m1, umax));
-  EXPECT_FALSE(safe_cmp::Le(umax, m1));
-  EXPECT_TRUE(safe_cmp::Le(umax, umax));
+  static_assert(safe_cmp::Le(m1, m1), "");
+  static_assert(safe_cmp::Le(m1, umax), "");
+  static_assert(!safe_cmp::Le(umax, m1), "");
+  static_assert(safe_cmp::Le(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Le(1, 2));
-  EXPECT_TRUE(safe_cmp::Le(1, 2.0));
-  EXPECT_TRUE(safe_cmp::Le(1.0, 2));
-  EXPECT_TRUE(safe_cmp::Le(1.0, 2.0));
-  EXPECT_FALSE(safe_cmp::Le(2, 1));
-  EXPECT_FALSE(safe_cmp::Le(2, 1.0));
-  EXPECT_FALSE(safe_cmp::Le(2.0, 1));
-  EXPECT_FALSE(safe_cmp::Le(2.0, 1.0));
+  static_assert(safe_cmp::Le(1, 2), "");
+  static_assert(safe_cmp::Le(1, 2.0), "");
+  static_assert(safe_cmp::Le(1.0, 2), "");
+  static_assert(safe_cmp::Le(1.0, 2.0), "");
+  static_assert(!safe_cmp::Le(2, 1), "");
+  static_assert(!safe_cmp::Le(2, 1.0), "");
+  static_assert(!safe_cmp::Le(2.0, 1), "");
+  static_assert(!safe_cmp::Le(2.0, 1.0), "");
 
-  EXPECT_TRUE(safe_cmp::Le(2, 2));
-  EXPECT_TRUE(safe_cmp::Le(2, 2.0));
-  EXPECT_TRUE(safe_cmp::Le(2.0, 2));
-  EXPECT_TRUE(safe_cmp::Le(2.0, 2.0));
+  static_assert(safe_cmp::Le(2, 2), "");
+  static_assert(safe_cmp::Le(2, 2.0), "");
+  static_assert(safe_cmp::Le(2.0, 2), "");
+  static_assert(safe_cmp::Le(2.0, 2.0), "");
 
   EXPECT_TRUE(safe_cmp::Le(p1, p1));
   EXPECT_TRUE(safe_cmp::Le(p1, p2));
@@ -277,48 +277,48 @@
 }
 
 TEST(SafeCmpTest, Gt) {
-  EXPECT_FALSE(safe_cmp::Gt(-1, 2));
-  EXPECT_FALSE(safe_cmp::Gt(-1, 2u));
-  EXPECT_TRUE(safe_cmp::Gt(2, -1));
-  EXPECT_TRUE(safe_cmp::Gt(2u, -1));
+  static_assert(!safe_cmp::Gt(-1, 2), "");
+  static_assert(!safe_cmp::Gt(-1, 2u), "");
+  static_assert(safe_cmp::Gt(2, -1), "");
+  static_assert(safe_cmp::Gt(2u, -1), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(1, 2));
-  EXPECT_FALSE(safe_cmp::Gt(1, 2u));
-  EXPECT_FALSE(safe_cmp::Gt(1u, 2));
-  EXPECT_FALSE(safe_cmp::Gt(1u, 2u));
-  EXPECT_TRUE(safe_cmp::Gt(2, 1));
-  EXPECT_TRUE(safe_cmp::Gt(2, 1u));
-  EXPECT_TRUE(safe_cmp::Gt(2u, 1));
-  EXPECT_TRUE(safe_cmp::Gt(2u, 1u));
+  static_assert(!safe_cmp::Gt(1, 2), "");
+  static_assert(!safe_cmp::Gt(1, 2u), "");
+  static_assert(!safe_cmp::Gt(1u, 2), "");
+  static_assert(!safe_cmp::Gt(1u, 2u), "");
+  static_assert(safe_cmp::Gt(2, 1), "");
+  static_assert(safe_cmp::Gt(2, 1u), "");
+  static_assert(safe_cmp::Gt(2u, 1), "");
+  static_assert(safe_cmp::Gt(2u, 1u), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(2, 2));
-  EXPECT_FALSE(safe_cmp::Gt(2, 2u));
-  EXPECT_FALSE(safe_cmp::Gt(2u, 2));
-  EXPECT_FALSE(safe_cmp::Gt(2u, 2u));
+  static_assert(!safe_cmp::Gt(2, 2), "");
+  static_assert(!safe_cmp::Gt(2, 2u), "");
+  static_assert(!safe_cmp::Gt(2u, 2), "");
+  static_assert(!safe_cmp::Gt(2u, 2u), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(imin, imin));
-  EXPECT_FALSE(safe_cmp::Gt(imin, umax));
-  EXPECT_TRUE(safe_cmp::Gt(umax, imin));
-  EXPECT_FALSE(safe_cmp::Gt(umax, umax));
+  static_assert(!safe_cmp::Gt(imin, imin), "");
+  static_assert(!safe_cmp::Gt(imin, umax), "");
+  static_assert(safe_cmp::Gt(umax, imin), "");
+  static_assert(!safe_cmp::Gt(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(m1, m1));
-  EXPECT_FALSE(safe_cmp::Gt(m1, umax));
-  EXPECT_TRUE(safe_cmp::Gt(umax, m1));
-  EXPECT_FALSE(safe_cmp::Gt(umax, umax));
+  static_assert(!safe_cmp::Gt(m1, m1), "");
+  static_assert(!safe_cmp::Gt(m1, umax), "");
+  static_assert(safe_cmp::Gt(umax, m1), "");
+  static_assert(!safe_cmp::Gt(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(1, 2));
-  EXPECT_FALSE(safe_cmp::Gt(1, 2.0));
-  EXPECT_FALSE(safe_cmp::Gt(1.0, 2));
-  EXPECT_FALSE(safe_cmp::Gt(1.0, 2.0));
-  EXPECT_TRUE(safe_cmp::Gt(2, 1));
-  EXPECT_TRUE(safe_cmp::Gt(2, 1.0));
-  EXPECT_TRUE(safe_cmp::Gt(2.0, 1));
-  EXPECT_TRUE(safe_cmp::Gt(2.0, 1.0));
+  static_assert(!safe_cmp::Gt(1, 2), "");
+  static_assert(!safe_cmp::Gt(1, 2.0), "");
+  static_assert(!safe_cmp::Gt(1.0, 2), "");
+  static_assert(!safe_cmp::Gt(1.0, 2.0), "");
+  static_assert(safe_cmp::Gt(2, 1), "");
+  static_assert(safe_cmp::Gt(2, 1.0), "");
+  static_assert(safe_cmp::Gt(2.0, 1), "");
+  static_assert(safe_cmp::Gt(2.0, 1.0), "");
 
-  EXPECT_FALSE(safe_cmp::Gt(2, 2));
-  EXPECT_FALSE(safe_cmp::Gt(2, 2.0));
-  EXPECT_FALSE(safe_cmp::Gt(2.0, 2));
-  EXPECT_FALSE(safe_cmp::Gt(2.0, 2.0));
+  static_assert(!safe_cmp::Gt(2, 2), "");
+  static_assert(!safe_cmp::Gt(2, 2.0), "");
+  static_assert(!safe_cmp::Gt(2.0, 2), "");
+  static_assert(!safe_cmp::Gt(2.0, 2.0), "");
 
   EXPECT_FALSE(safe_cmp::Gt(p1, p1));
   EXPECT_FALSE(safe_cmp::Gt(p1, p2));
@@ -327,48 +327,48 @@
 }
 
 TEST(SafeCmpTest, Ge) {
-  EXPECT_FALSE(safe_cmp::Ge(-1, 2));
-  EXPECT_FALSE(safe_cmp::Ge(-1, 2u));
-  EXPECT_TRUE(safe_cmp::Ge(2, -1));
-  EXPECT_TRUE(safe_cmp::Ge(2u, -1));
+  static_assert(!safe_cmp::Ge(-1, 2), "");
+  static_assert(!safe_cmp::Ge(-1, 2u), "");
+  static_assert(safe_cmp::Ge(2, -1), "");
+  static_assert(safe_cmp::Ge(2u, -1), "");
 
-  EXPECT_FALSE(safe_cmp::Ge(1, 2));
-  EXPECT_FALSE(safe_cmp::Ge(1, 2u));
-  EXPECT_FALSE(safe_cmp::Ge(1u, 2));
-  EXPECT_FALSE(safe_cmp::Ge(1u, 2u));
-  EXPECT_TRUE(safe_cmp::Ge(2, 1));
-  EXPECT_TRUE(safe_cmp::Ge(2, 1u));
-  EXPECT_TRUE(safe_cmp::Ge(2u, 1));
-  EXPECT_TRUE(safe_cmp::Ge(2u, 1u));
+  static_assert(!safe_cmp::Ge(1, 2), "");
+  static_assert(!safe_cmp::Ge(1, 2u), "");
+  static_assert(!safe_cmp::Ge(1u, 2), "");
+  static_assert(!safe_cmp::Ge(1u, 2u), "");
+  static_assert(safe_cmp::Ge(2, 1), "");
+  static_assert(safe_cmp::Ge(2, 1u), "");
+  static_assert(safe_cmp::Ge(2u, 1), "");
+  static_assert(safe_cmp::Ge(2u, 1u), "");
 
-  EXPECT_TRUE(safe_cmp::Ge(2, 2));
-  EXPECT_TRUE(safe_cmp::Ge(2, 2u));
-  EXPECT_TRUE(safe_cmp::Ge(2u, 2));
-  EXPECT_TRUE(safe_cmp::Ge(2u, 2u));
+  static_assert(safe_cmp::Ge(2, 2), "");
+  static_assert(safe_cmp::Ge(2, 2u), "");
+  static_assert(safe_cmp::Ge(2u, 2), "");
+  static_assert(safe_cmp::Ge(2u, 2u), "");
 
-  EXPECT_TRUE(safe_cmp::Ge(imin, imin));
-  EXPECT_FALSE(safe_cmp::Ge(imin, umax));
-  EXPECT_TRUE(safe_cmp::Ge(umax, imin));
-  EXPECT_TRUE(safe_cmp::Ge(umax, umax));
+  static_assert(safe_cmp::Ge(imin, imin), "");
+  static_assert(!safe_cmp::Ge(imin, umax), "");
+  static_assert(safe_cmp::Ge(umax, imin), "");
+  static_assert(safe_cmp::Ge(umax, umax), "");
 
-  EXPECT_TRUE(safe_cmp::Ge(m1, m1));
-  EXPECT_FALSE(safe_cmp::Ge(m1, umax));
-  EXPECT_TRUE(safe_cmp::Ge(umax, m1));
-  EXPECT_TRUE(safe_cmp::Ge(umax, umax));
+  static_assert(safe_cmp::Ge(m1, m1), "");
+  static_assert(!safe_cmp::Ge(m1, umax), "");
+  static_assert(safe_cmp::Ge(umax, m1), "");
+  static_assert(safe_cmp::Ge(umax, umax), "");
 
-  EXPECT_FALSE(safe_cmp::Ge(1, 2));
-  EXPECT_FALSE(safe_cmp::Ge(1, 2.0));
-  EXPECT_FALSE(safe_cmp::Ge(1.0, 2));
-  EXPECT_FALSE(safe_cmp::Ge(1.0, 2.0));
-  EXPECT_TRUE(safe_cmp::Ge(2, 1));
-  EXPECT_TRUE(safe_cmp::Ge(2, 1.0));
-  EXPECT_TRUE(safe_cmp::Ge(2.0, 1));
-  EXPECT_TRUE(safe_cmp::Ge(2.0, 1.0));
+  static_assert(!safe_cmp::Ge(1, 2), "");
+  static_assert(!safe_cmp::Ge(1, 2.0), "");
+  static_assert(!safe_cmp::Ge(1.0, 2), "");
+  static_assert(!safe_cmp::Ge(1.0, 2.0), "");
+  static_assert(safe_cmp::Ge(2, 1), "");
+  static_assert(safe_cmp::Ge(2, 1.0), "");
+  static_assert(safe_cmp::Ge(2.0, 1), "");
+  static_assert(safe_cmp::Ge(2.0, 1.0), "");
 
-  EXPECT_TRUE(safe_cmp::Ge(2, 2));
-  EXPECT_TRUE(safe_cmp::Ge(2, 2.0));
-  EXPECT_TRUE(safe_cmp::Ge(2.0, 2));
-  EXPECT_TRUE(safe_cmp::Ge(2.0, 2.0));
+  static_assert(safe_cmp::Ge(2, 2), "");
+  static_assert(safe_cmp::Ge(2, 2.0), "");
+  static_assert(safe_cmp::Ge(2.0, 2), "");
+  static_assert(safe_cmp::Ge(2.0, 2.0), "");
 
   EXPECT_TRUE(safe_cmp::Ge(p1, p1));
   EXPECT_FALSE(safe_cmp::Ge(p1, p2));
@@ -381,14 +381,14 @@
   enum { e2 = 13 };
   enum E3 : unsigned { e3 = 13 };
   enum : unsigned { e4 = 13 };
-  EXPECT_TRUE(safe_cmp::Eq(13, e1));
-  EXPECT_TRUE(safe_cmp::Eq(13u, e1));
-  EXPECT_TRUE(safe_cmp::Eq(13, e2));
-  EXPECT_TRUE(safe_cmp::Eq(13u, e2));
-  EXPECT_TRUE(safe_cmp::Eq(13, e3));
-  EXPECT_TRUE(safe_cmp::Eq(13u, e3));
-  EXPECT_TRUE(safe_cmp::Eq(13, e4));
-  EXPECT_TRUE(safe_cmp::Eq(13u, e4));
+  static_assert(safe_cmp::Eq(13, e1), "");
+  static_assert(safe_cmp::Eq(13u, e1), "");
+  static_assert(safe_cmp::Eq(13, e2), "");
+  static_assert(safe_cmp::Eq(13u, e2), "");
+  static_assert(safe_cmp::Eq(13, e3), "");
+  static_assert(safe_cmp::Eq(13u, e3), "");
+  static_assert(safe_cmp::Eq(13, e4), "");
+  static_assert(safe_cmp::Eq(13u, e4), "");
 }
 
 }  // namespace rtc