writing directly to std::string internal buffers

Question

I was looking for a way to stuff some data into a string across a DLL boundary. Because we use different compilers, all our dll interfaces are simple char*.

Is ther

Answer 1

I'm not sure the standard guarantees that the data in a std::string is stored as a char*. The most portable way I can think of is to use a std::vector, which is guaranteed to store its data in a continuous chunk of memory:

std::vector buffer(100);
FunctionInDLL(&buffer[0], buffer.size());
std::string stringToFillIn(&buffer[0]);

This will of course require the data to be copied twice, which is a bit inefficient.