src/kenlm/util/string_stream.hh

#ifndef UTIL_STRING_STREAM_H
#define UTIL_STRING_STREAM_H

#include "util/fake_ostream.hh"

#include <cassert>
#include <string>

namespace util {

class StringStream : public FakeOStream<StringStream> {
  public:
    // Semantics: appends to string.  Remember to clear first!
    explicit StringStream(std::string &out)
      : out_(out) {}

    StringStream &flush() { return *this; }

    StringStream &write(const void *data, std::size_t length) {
      out_.append(static_cast<const char*>(data), length);
      return *this;
    }

  protected:
    friend class FakeOStream<StringStream>;
    char *Ensure(std::size_t amount) {
      std::size_t current = out_.size();
      out_.resize(out_.size() + amount);
      return &out_[current];
    }

    void AdvanceTo(char *to) {
      assert(to <= &*out_.end());
      assert(to >= &*out_.begin());
      out_.resize(to - &*out_.begin());
    }

  private:
    std::string &out_;
};

} // namespace

#endif // UTIL_STRING_STREAM_H