CODEWITHSUNDEEP
c++serializationnullprotocol-buffersstdstring
Ramya
Ramya

Reputation: 65

How to assign Google protocol buffer SerializeAsString() output which contains embedded nulls to std::string?

I am trying to serialize the message as string in C++ using google protocol buffer and assign the serialized result (which contains embedded nulls in it) to std::string. Following is my code:

std::string result = message.SerializeAsString();

It is ignoring the characters after the first \0 character. result is not having the full serialized string. I tried the following which explicitly specifies the length.

int size = message.ByteSize();
std::string result(std::string(message.SerializeAsString()), size);

It is also not working for me. Is there any other way to do this ?

Thanks in advance.

Upvotes: 1

Views: 3904

Answers (2)

Kenton Varda
Kenton Varda

Reputation: 45181

There is no problem storing NUL bytes in std::strings. You can just assign the string normally. Both of your code snippets should work fine.

The problem comes if you ever call .c_str() and try to pass the string to something expecting const char*. At this point, the receiver of the const char* doesn't know the size of the string so assumes it ends at the first NUL byte. So, don't do that -- always make sure you're either passing the std::string whole, or that your passing both a pointer and a size (from .size()).

You commented on another answer that you need to convert to std::wstring. EDIT: I moved my comments on this to your other question.

Upvotes: 2

bashrc
bashrc

Reputation: 4835

std::string result(message.SerializeAsString(), size);

when you are creating the temporary string

std::string(message.SerializeAsString())

This part consumes the embedded nulls.

Upvotes: 1

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