Re: std::basic_string<> contiguous data?

"James Kanze" <>
15 Jan 2007 18:14:48 -0500
Adam White wrote:

I've been writing a NetString class for network transmissions, which has
been internally implemented using a std::string.

To read data into the NetString from a network socket, I'd planned to
pre-allocate a large std::string (to use as a buffer), then slurp data
directly from the socket into the string via pointer indirection or by
using the std::string::data() array.

The pointer returned by std::string::data() is const; you can't
modify the memory it points to.

But is std::basic_string<>'s data guaranteed to be in a contiguous array?


I believe that TR1 clarified the intention that std::vector<> data be
stored contiguously - is that also true of std::basic_string<> ?


Even if it is contiguous, there is nothing which guarantees that
modifications through the pointer returned by data() will
affect the value of the string itself.

(In practice, of course, I think you'll probably be able to get
away with it in all real implementations:-).)

James Kanze (GABI Software)
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