Re: Storing byte stream in std::string

Barry <>
Thu, 03 Jan 2008 10:57:43 +0800
TBass wrote:


I'm moving a socket library I wrote from C to C++. In the C version, I
had to malloc char arrays to store incoming communication. My hope was
to use std::string in C++, but then I realized a problem.

While '\0' is a valid string terminator for text, for my purposes it
is a problem. My program regularly gets '\0' as a value (Modbus/RTU
and TCP pass register values as the actual values, not the ASCII
chart). That would be a problem with std::string, I would think, since
it would see the '\0' as the end of a character stream, while, in
actuality, it would be all over the string and not indicate the
termination of the stream.

the representation of std::string doesn't treat '\0' a special
character, which means you an push_back any '\0' at any time.

My question is whether I can write a stream of bytes to std::string,
read the length, and be able to get the whole string back. I expect
that I wouldn't be able to use any of the string functions, but could
I at least get the number of bytes store and get those bytes back at a
later time?

Or should I try a different container?

Well, std::string does NOT guarantee the underlaying memory continuous.

I think std::vector is more like a buffer here, which guarantees
continuous underlying memory.

std::vector<char> buffer;
&buffer[0]; // get the pointer to the first cell.

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