chore(nebula_common): add utility to get std::string from <<streamabl…

…e types

nebula_common/include/nebula_common/util/string_conversions.hpp

@@ -0,0 +1,44 @@
+// Copyright 2024 TIER IV, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <ostream>
+#include <sstream>
+#include <string>
+#include <type_traits>
+
+namespace nebula::util
+{
+
+template <typename T, typename = void>
+struct IsStreamable : std::false_type
+{
+};
+
+template <typename T>
+struct IsStreamable<T, std::void_t<decltype(std::declval<std::ostream &>() << std::declval<T>())> >
+: std::true_type
+{
+};
+
+template <typename T>
+std::enable_if_t<IsStreamable<T>::value, std::string> to_string(const T & value)
+{
+  std::stringstream ss{};
+  ss << value;
+  return ss.str();
+}
+
+}  // namespace nebula::util