Enable modernize-std-numbers clang-tidy checker, fix findings

.clang-tidy

@@ -64,7 +64,6 @@ Checks: [-*,
          # These are features in newer version of C++ that we don't have
          # access to yet.
          -modernize-use-std-format,
-         -modernize-use-std-numbers,
          -modernize-use-std-print,
 ]
 

src/probabilistic/BloomFilter.cc

@@ -5,6 +5,7 @@
 #include <cinttypes>
 #include <cmath>
 #include <limits>
+#include <numbers>
 
 #include "zeek/Reporter.h"
 #include "zeek/broker/Data.h"
@@ -86,13 +87,13 @@ bool BloomFilter::DoUnserializeData(BrokerDataView data) {
 }
 
 size_t BasicBloomFilter::M(double fp, size_t capacity) {
-    double ln2 = std::log(2);
+    double ln2 = std::numbers::ln2;
     return std::ceil(-(capacity * std::log(fp) / ln2 / ln2));
 }
 
 size_t BasicBloomFilter::K(size_t cells, size_t capacity) {
     double frac = static_cast<double>(cells) / static_cast<double>(capacity);
-    return std::ceil(frac * std::log(2));
+    return std::ceil(frac * std::numbers::ln2);
 }
 
 bool BasicBloomFilter::Empty() const { return bits->AllZero(); }

src/probabilistic/CardinalityCounter.cc

@@ -5,6 +5,7 @@
 #include <cinttypes>
 #include <cmath>
 #include <cstdint>
+#include <numbers>
 #include <utility>
 
 #include "zeek/Reporter.h"
@@ -13,7 +14,7 @@
 namespace zeek::probabilistic::detail {
 
 int CardinalityCounter::OptimalB(double error, double confidence) const {
-    double initial_estimate = 2 * (log(1.04) - log(error)) / log(2);
+    double initial_estimate = 2 * (log(1.04) - log(error)) / std::numbers::ln2;
     int answer = (int)floor(initial_estimate);
 
     // k is the number of standard deviations that we have to go to have
@@ -24,7 +25,7 @@ int CardinalityCounter::OptimalB(double error, double confidence) const {
     do {
         answer++;
         k = pow(2, (answer - initial_estimate) / 2);
-    } while ( erf(k / sqrt(2)) < confidence );
+    } while ( erf(k / std::numbers::sqrt2) < confidence );
 
     return answer;
 }