Use ranges CPOs directly

Author: ldionne

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

@@ -62,7 +62,7 @@ static void bm_vector_bool(std::string operation_name, Operation copy) {
 
 int main(int argc, char** argv) {
   auto std_copy    = [](auto first, auto last, auto out) { return std::copy(first, last, out); };
-  auto ranges_copy = [](auto first, auto last, auto out) { return std::ranges::copy(first, last, out); };
+  auto ranges_copy = std::ranges::copy;
 
   // std::copy
   bm_general<std::vector<int>>("std::copy(vector<int>)", std_copy);

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

@@ -62,9 +62,7 @@ static void bm_vector_bool(std::string operation_name, Operation copy_backward)
 
 int main(int argc, char** argv) {
   auto std_copy_backward    = [](auto first, auto last, auto out) { return std::copy_backward(first, last, out); };
-  auto ranges_copy_backward = [](auto first, auto last, auto out) {
-    return std::ranges::copy_backward(first, last, out);
-  };
+  auto ranges_copy_backward = std::ranges::copy_backward;
 
   // std::copy
   bm_general<std::vector<int>>("std::copy_backward(vector<int>)", std_copy_backward);

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

@@ -76,9 +76,7 @@ void bm_copy_entire_range(std::string operation_name, Operation copy_if) {
 
 int main(int argc, char** argv) {
   auto std_copy_if    = [](auto first, auto last, auto out, auto pred) { return std::copy_if(first, last, out, pred); };
-  auto ranges_copy_if = [](auto first, auto last, auto out, auto pred) {
-    return std::ranges::copy_if(first, last, out, pred);
-  };
+  auto ranges_copy_if = std::ranges::copy_if;
 
   // std::copy_if
   bm_copy_every_other_element<std::vector<int>>("std::copy_if(vector<int>) (every other)", std_copy_if);

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

@@ -61,7 +61,7 @@ static void bm_vector_bool(std::string operation_name, Operation copy_n) {
 
 int main(int argc, char** argv) {
   auto std_copy_n    = [](auto first, auto n, auto out) { return std::copy_n(first, n, out); };
-  auto ranges_copy_n = [](auto first, auto n, auto out) { return std::ranges::copy_n(first, n, out); };
+  auto ranges_copy_n = std::ranges::copy_n;
 
   // std::copy_n
   bm_general<std::vector<int>>("std::copy_n(vector<int>)", std_copy_n);