// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// https://developers.google.com/protocol-buffers/
//
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// modification, are permitted provided that the following conditions are
// met:
//
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// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
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// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
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// from google3/util/gtl/stl_util.h

#ifndef GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__
#define GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__

#include <algorithm>

#include "google/protobuf/stubs/common.h"

// Must be last.
#include "google/protobuf/port_def.inc"  // NOLINT

namespace google {
namespace protobuf {

// Return a mutable char* pointing to a string's internal buffer,
// which may not be null-terminated. Writing through this pointer will
// modify the string.
//
// string_as_array(&str)[i] is valid for 0 <= i < str.size() until the
// next call to a string method that invalidates iterators.
//
// As of 2006-04, there is no standard-blessed way of getting a
// mutable reference to a string's internal buffer. However, issue 530
// (http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#530)
// proposes this as the method. According to Matt Austern, this should
// already work on all current implementations.
inline char* string_as_array(std::string* str) {
  // DO NOT USE const_cast<char*>(str->data())! See the unittest for why.
  return str->empty() ? nullptr : &*str->begin();
}

}  // namespace protobuf
}  // namespace google

#include "google/protobuf/port_undef.inc"  // NOLINT

#endif  // GOOGLE_PROTOBUF_STUBS_STL_UTIL_H__