Re: Save a vector inside a structure.

Jensen Somers wrote:


Yes and no.

The actual data in a vector, the internals so to speak, probably, most
likely, consist of some pointers. I strongly suspect that you want the
data that the vector presents as part of it's interface.


I assume here that you're somehow taking sizeof(SaveData) and then
writing out that number of chars to disk starting from the address of an
instance of SaveData.

I don't think that the data which should be in the vector is corrupt,
but rather it's not what you expected it to be. It's also unlikely to
be useful to persist the internal data in the vector.


Shouldn't make a difference. Given
    std::vector<int> v;
sizeof(v) isn't going to change, but v.size() probably will.


Then I think you might try allocating some memory, populating it, and
saving that. You may run into some platform dependencies here.

You may want to see if you can use some other mechanism to save the data
to EEPROM. Maybe you can reserve some space and save blocks at a time
to that area?


Here's the start of a class that might help. All the data will end up
in one contiguous area of memory. This isn't the only way to do
something like this and it's probably not the best way. More of a point
of departure than a destination.

class SaveDataToSaveData {
    size_t size;
    int *p;

    SaveDataToSaveData(const SaveData &s)
        :
        size( 2 + s.order.size() ), // beware magic numbers
        p(new int[ size ] )
    {
        size_t i=0;
        p[i++] = s.first;
        p[i++] = s.last;
        for(size_t j=0; j<s.order.size(); j++) {
            p[i++] = s.order.at(j);
        }
    }

    ~SaveDataToSaveData() { delete [] p; }

    // just for testing
    void dump() const {
        std::copy(p, p+size, std::ostream_iterator<int>(std::cout," "));
    }
};

LR

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