text: // Copyright 2018 Xiaomi, Inc.  All rights reserved.
  //
  // 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.
  
  #ifndef MACE_UTILS_STRING_UTIL_H_
  #define MACE_UTILS_STRING_UTIL_H_
  
  #include <sstream>
  #include <string>
  #include <vector>
  
  namespace mace {
  namespace string_util {
  
  inline void MakeStringInternal(std::stringstream & /*ss*/) {}
  
  template <typename T>
  inline void MakeStringInternal(std::stringstream &ss, const T &t) {
    ss << t;
  }
  
  template <typename T, typename... Args>
  inline void MakeStringInternal(std::stringstream &ss,
                                 const T &t,
                                 const Args &... args) {
    MakeStringInternal(ss, t);
    MakeStringInternal(ss, args...);
  }
  
  class StringFormatter {
   public:
    static std::string Table(const std::string &title,
                             const std::vector<std::string> &header,
                             const std::vector<std::vector<std::string>> &data);
  };
  
  }  // namespace string_util
  
  template <typename... Args>
  std::string MakeString(const Args &... args) {
    std::stringstream ss;
    string_util::MakeStringInternal(ss, args...);
    return ss.str();
  }
  
  template <typename T>
  std::string MakeListString(const T *args, size_t size) {
    std::stringstream ss;
    ss << "[";
    for (size_t i = 0; i < size; ++i) {
      ss << args[i];
      if (i < size - 1) {
        ss << ", ";
      }
    }
    ss << "]";
    return ss.str();
  }
  
  template <typename T>
  std::string MakeString(const std::vector<T> &args) {
    return MakeListString(args.data(), args.size());
  }
  
  // Specializations for already-a-string types.
  template <>
  inline std::string MakeString(const std::string &str) {
    return str;
  }
  
  inline std::string MakeString(const char *c_str) { return std::string(c_str); }
  
  }  // namespace mace
  
  #endif  // MACE_UTILS_STRING_UTIL_H_
  