bitsery/examples/file_stream.cpp

#include <bitsery/bitsery.h>
// in order to work with streams include stream adapter
#include <bitsery/adapter/stream.h>
#include <fstream>
#include <iostream>

enum class MyEnum : uint16_t
{
  V1,
  V2,
  V3
};
struct MyStruct
{
  uint32_t i;
  MyEnum e;
  double f;
};

// define how object should be serialized/deserialized
template<typename S>
void
serialize(S& s, MyStruct& o)
{
  s.value4b(o.i);
  s.value2b(o.e);
  s.value8b(o.f);
}

int
main()
{
  // set some random data
  MyStruct data{ 8941, MyEnum::V2, 0.045 };
  MyStruct res{};

  // open file stream for writing and reading
  auto fileName = "test_file.bin";
  std::fstream s{ fileName, s.binary | s.trunc | s.out };
  if (!s.is_open()) {
    std::cout << "cannot open " << fileName << " for writing\n";
    return 0;
  }

  // we cannot use quick serialization function, because streams cannot use
  // writtenBytesCount method
  bitsery::Serializer<bitsery::OutputBufferedStreamAdapter> ser{ s };
  ser.object(data);
  // flush to writer
  ser.adapter().flush();
  s.close();
  // reopen for reading

  s.open(fileName, s.binary | s.in);
  if (!s.is_open()) {
    std::cout << "cannot open " << fileName << " for reading\n";
    return 0;
  }

  // same as serialization, but returns deserialization state as a pair
  // first = error code, second = is buffer was successfully read from begin to
  // the end.
  auto state =
    bitsery::quickDeserialization<bitsery::InputStreamAdapter>(s, res);

  assert(state.first == bitsery::ReaderError::NoError && state.second);
  assert(data.f == res.f && data.i == res.i && data.e == res.e);
}