std::tie does not work on some compilers (simdjson#567)

lemire · web-flow · commit 6cefeb338bd9 · 2020-03-19T16:56:45.000-04:00
* std::tie workaround.

* Cleaner solution
diff --git a/benchmark/benchmarker.h b/benchmark/benchmarker.h
@@ -263,7 +263,7 @@ struct benchmarker {
     : filename(_filename), collector(_collector), stats(NULL) {
     verbose() << "[verbose] loading " << filename << endl;
     simdjson::error_code error;
-    std::tie(this->json, error) = padded_string::load(filename);
+    padded_string::load(filename).tie(this->json, error);
     if (error) {
       exit_error(string("Could not load the file ") + filename);
     }
diff --git a/include/simdjson/error.h b/include/simdjson/error.h
@@ -128,6 +128,16 @@ struct simdjson_result : public std::pair<T, error_code> {
  */
 template<typename T>
 struct simdjson_move_result : std::pair<T, error_code> {
+  /**
+   * Move the value and the error to the provided variables.
+   */
+  void tie(T& t, error_code & e) {
+    // on the clang compiler that comes with current macOS (Apple clang version 11.0.0),
+    // std::tie(this->json, error) = padded_string::load(filename);
+    // fails with "benchmark/benchmarker.h:266:33: error: no viable overloaded '='""
+    t = std::move(this->first);
+    e = std::move(this->second);
+  }
   /**
    * The error.
    */

Original file line number	Diff line number	Diff line change
`@@ -263,7 +263,7 @@ struct benchmarker {`
`263`	`263`	`: filename(_filename), collector(_collector), stats(NULL) {`
`264`	`264`	`verbose() << "[verbose] loading " << filename << endl;`
`265`	`265`	`simdjson::error_code error;`
`266`		`- std::tie(this->json, error) = padded_string::load(filename);`
	`266`	`+ padded_string::load(filename).tie(this->json, error);`
`267`	`267`	`if (error) {`
`268`	`268`	`exit_error(string("Could not load the file ") + filename);`
`269`	`269`	`}`