Use "static_assert" in lieu of "COMPILE_ASSERT" in courgete

courgette/difference_estimator.cc

Index: courgette/difference_estimator.cc
diff --git a/courgette/difference_estimator.cc b/courgette/difference_estimator.cc
index 3b2cddc94dec0099107bfd6e643d2fc997cc1345..f2f09e15cc9cd92b6f0adcbdc88ef76ed09dd14f 100644
--- a/courgette/difference_estimator.cc
+++ b/courgette/difference_estimator.cc
@@ -18,7 +18,8 @@ const int kTupleSize = 4;
 
 namespace {
 
-COMPILE_ASSERT(kTupleSize >= 4 && kTupleSize <= 8, kTupleSize_between_4_and_8);
+static_assert(kTupleSize >= 4 && kTupleSize <= 8,
+              "kTupleSize should be between 4 and 8");
 
 size_t HashTuple(const uint8* source) {
   size_t hash1 = *reinterpret_cast<const uint32*>(source);