Attaching basic_string to preallocated buffer

[Alvin777]

I'd like to have data file with many strings and load them at once
using MapViewOfFile[Ex] and unload with UnmapViewOfFile. So I wouldn't
have to allocate memory for each string on heap.

How can I use basic_string<> attaching them to pointer to string
within mapped space so it wouldn't copy that string to internal
buffer?

 

[Bob Hairgrove]

I'd like to have data file with many strings and load them at once
using MapViewOfFile[Ex] and unload with UnmapViewOfFile. So I wouldn't
have to allocate memory for each string on heap.

How can I use basic_string<> attaching them to pointer to string
within mapped space so it wouldn't copy that string to internal
buffer?

You might find it easier to use std::iostream etc.

I don't think you can do this with basic_string. But I would be gladly
poven wrong <g>.

 

[John Harrison]

I'd like to have data file with many strings and load them at once
using MapViewOfFile[Ex] and unload with UnmapViewOfFile. So I wouldn't
have to allocate memory for each string on heap.

How can I use basic_string<> attaching them to pointer to string
within mapped space so it wouldn't copy that string to internal
buffer?

You cannot. Obviously there would be difficulties if, for instance,
std::string wanted to reallocate its buffer. It would be awkward to keep
track of whether it had a reallocated buffer, or one that was supplied by
the user.

I suggest you write your own string class that does what you want
(presumably one that never reallocates its buffer).

class StaticString
{
public:
StaticString(const char*);
...
private:
const char* buffer;
};

john