Take by value in predicates

Author: ldionne

libcxx/test/benchmarks/algorithms/nonmodifying/is_permutation.bench.cpp

@@ -27,21 +27,21 @@ int main(int argc, char** argv) {
     return std::is_permutation(first1, last1, first2, last2);
   };
   auto std_is_permutation_3leg_pred = [](auto first1, auto last1, auto first2, auto) {
-    return std::is_permutation(first1, last1, first2, [](auto& x, auto& y) {
+    return std::is_permutation(first1, last1, first2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;
     });
   };
   auto std_is_permutation_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::is_permutation(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::is_permutation(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;
     });
   };
   auto ranges_is_permutation_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::ranges::is_permutation(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::ranges::is_permutation(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;

libcxx/test/benchmarks/algorithms/nonmodifying/mismatch.bench.cpp

@@ -26,21 +26,21 @@ int main(int argc, char** argv) {
     return std::mismatch(first1, last1, first2, last2);
   };
   auto std_mismatch_3leg_pred = [](auto first1, auto last1, auto first2, auto) {
-    return std::mismatch(first1, last1, first2, [](auto& x, auto& y) {
+    return std::mismatch(first1, last1, first2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;
     });
   };
   auto std_mismatch_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::mismatch(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::mismatch(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;
     });
   };
   auto ranges_mismatch_4leg_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::ranges::mismatch(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::ranges::mismatch(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;

libcxx/test/benchmarks/algorithms/nonmodifying/search.bench.cpp

@@ -24,14 +24,14 @@ int main(int argc, char** argv) {
     return std::search(first1, last1, first2, last2);
   };
   auto std_search_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::search(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::search(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;
     });
   };
   auto ranges_search_pred = [](auto first1, auto last1, auto first2, auto last2) {
-    return std::ranges::search(first1, last1, first2, last2, [](auto& x, auto& y) {
+    return std::ranges::search(first1, last1, first2, last2, [](auto x, auto y) {
       benchmark::DoNotOptimize(x);
       benchmark::DoNotOptimize(y);
       return x == y;