include/wabt/string-util.h

/*
 * Copyright 2017 WebAssembly Community Group participants
 *
 * 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 WABT_STRING_UTIL_H_
#define WABT_STRING_UTIL_H_

#include <string>
#include <string_view>

namespace wabt {

inline std::string& operator+=(std::string& x, std::string_view y) {
  x.append(y.data(), y.size());
  return x;
}

inline std::string operator+(std::string_view x, std::string_view y) {
  std::string s;
  s.reserve(x.size() + y.size());
  s.append(x.data(), x.size());
  s.append(y.data(), y.size());
  return s;
}

inline std::string operator+(const std::string& x, std::string_view y) {
  return std::string_view(x) + y;
}

inline std::string operator+(std::string_view x, const std::string& y) {
  return x + std::string_view(y);
}

inline std::string operator+(const char* x, std::string_view y) {
  return std::string_view(x) + y;
}

inline std::string operator+(std::string_view x, const char* y) {
  return x + std::string_view(y);
}

inline void cat_concatenate(std::string&) {}

template <typename T, typename... Ts>
void cat_concatenate(std::string& s, const T& t, const Ts&... args) {
  s += t;
  cat_concatenate(s, args...);
}

inline size_t cat_compute_size() {
  return 0;
}

template <typename T, typename... Ts>
size_t cat_compute_size(const T& t, const Ts&... args) {
  return std::string_view(t).size() + cat_compute_size(args...);
}

// Is able to concatenate any combination of string/string_view/char*
template <typename... Ts>
std::string cat(const Ts&... args) {
  std::string s;
  s.reserve(cat_compute_size(args...));
  cat_concatenate(s, args...);
  return s;
}

}  // namespace wabt

#endif  // WABT_STRING_UTIL_H_