Change raw loop to std::algorithm copy

common.cpp

@@ -2,6 +2,7 @@
 
 #include <algorithm>
 #include <vector>
+#include <iterator>
 
 const int HIST_MAX = 20;
 
@@ -41,8 +42,8 @@ void show_histogram(const Caches& cc, std::string Cache::*ptr, const std::string
 
 	for (auto el : cc)
 		histogram[el.*ptr]++;
-	for (auto el : histogram)
-		pairs.push_back(el);
+	std::copy(histogram.begin(), histogram.end(), std::back_inserter(pairs));
+
 	if (sort_by_val)
 		sort(pairs.begin(), pairs.end(), [&](std::pair<std::string, int>& a, std::pair<std::string, int>& b) { return a.second > b.second; });
 	else