Don't take references in predicates

Author: ldionne

libcxx/test/benchmarks/algorithms/modifying/remove_copy_if.bench.cpp

@@ -44,7 +44,7 @@ int main(int argc, char** argv) {
             for ([[maybe_unused]] auto _ : st) {
               benchmark::DoNotOptimize(c);
               benchmark::DoNotOptimize(out);
-              auto pred = [&x](auto& element) {
+              auto pred = [&x](auto element) {
                 benchmark::DoNotOptimize(element);
                 return element == x;
               };
@@ -85,7 +85,7 @@ int main(int argc, char** argv) {
             for ([[maybe_unused]] auto _ : st) {
               benchmark::DoNotOptimize(c);
               benchmark::DoNotOptimize(out);
-              auto pred = [&](auto& element) {
+              auto pred = [&](auto element) {
                 benchmark::DoNotOptimize(element);
                 return element == x;
               };

libcxx/test/benchmarks/algorithms/modifying/remove_if.bench.cpp

@@ -44,7 +44,7 @@ int main(int argc, char** argv) {
               std::fill_n(std::fill_n(c[i].begin(), half, x), half, y);
             }
 
-            auto pred = [&](auto& element) {
+            auto pred = [&](auto element) {
               benchmark::DoNotOptimize(element);
               return element == x;
             };
@@ -102,7 +102,7 @@ int main(int argc, char** argv) {
               alternate(c[i].begin(), size);
             }
 
-            auto pred = [&](auto& element) {
+            auto pred = [&](auto element) {
               benchmark::DoNotOptimize(element);
               return element == x;
             };

libcxx/test/benchmarks/algorithms/modifying/replace_if.bench.cpp

@@ -46,7 +46,7 @@ int main(int argc, char** argv) {
             for ([[maybe_unused]] auto _ : st) {
               benchmark::DoNotOptimize(c);
               benchmark::DoNotOptimize(z);
-              auto pred = [&x](auto& element) {
+              auto pred = [&x](auto element) {
                 benchmark::DoNotOptimize(element);
                 return element == x;
               };
@@ -86,7 +86,7 @@ int main(int argc, char** argv) {
             for ([[maybe_unused]] auto _ : st) {
               benchmark::DoNotOptimize(c);
               benchmark::DoNotOptimize(z);
-              auto pred = [&x](auto& element) {
+              auto pred = [&x](auto element) {
                 benchmark::DoNotOptimize(element);
                 return element == x;
               };

libcxx/test/benchmarks/algorithms/modifying/transform.binary.bench.cpp

@@ -38,7 +38,7 @@ int main(int argc, char** argv) {
 
             std::vector<ValueType> out(size);
 
-            auto f = [](auto& x, auto& y) {
+            auto f = [](auto x, auto y) {
               benchmark::DoNotOptimize(x);
               benchmark::DoNotOptimize(y);
               return x + y;

libcxx/test/benchmarks/algorithms/modifying/transform.unary.bench.cpp

@@ -35,7 +35,7 @@ int main(int argc, char** argv) {
 
             std::vector<ValueType> out(size);
 
-            auto f = [](auto& element) {
+            auto f = [](auto element) {
               benchmark::DoNotOptimize(element);
               return element;
             };

libcxx/test/benchmarks/algorithms/modifying/unique_copy_pred.bench.cpp

@@ -41,7 +41,7 @@ int main(int argc, char** argv) {
 
             std::vector<ValueType> out(size);
 
-            auto pred = [](auto& a, auto& b) {
+            auto pred = [](auto a, auto b) {
               benchmark::DoNotOptimize(a);
               benchmark::DoNotOptimize(b);
               return a == b;
@@ -88,7 +88,7 @@ int main(int argc, char** argv) {
 
             std::vector<ValueType> out(size);
 
-            auto pred = [](auto& a, auto& b) {
+            auto pred = [](auto a, auto b) {
               benchmark::DoNotOptimize(a);
               benchmark::DoNotOptimize(b);
               return a == b;

libcxx/test/benchmarks/algorithms/modifying/unique_pred.bench.cpp

@@ -44,7 +44,7 @@ int main(int argc, char** argv) {
               std::fill_n(std::fill_n(c[i].begin(), half, x), half, y);
             }
 
-            auto pred = [](auto& a, auto& b) {
+            auto pred = [](auto a, auto b) {
               benchmark::DoNotOptimize(a);
               benchmark::DoNotOptimize(b);
               return a == b;
@@ -104,7 +104,7 @@ int main(int argc, char** argv) {
               alternate(c[i].begin(), size);
             }
 
-            auto pred = [](auto& a, auto& b) {
+            auto pred = [](auto a, auto b) {
               benchmark::DoNotOptimize(a);
               benchmark::DoNotOptimize(b);
               return a == b;