Question

I have got file with vector of :

typedef struct {
    float fX; ///< position X
    float fY; ///< position Y
    int iSize; ///< Size of point   
} structParams;

but I would like to read it to vector of nearly the same struct but without iSize

typedef struct {
    float fX; ///< position X eq. structParams.fX
    float fY; ///< position Y eq. structParams.fY
} structPositionParams;

Can I do this in similar way to

ifstream inStr("file.dat");
vector<structPositionParams>  oVector;
oVector.(numOfElements);
inStr.read((char*)&oVector[0], sizeof(structPositionParams) * numOfElements);
inStr.close();

Answer 1

You’ve got to utilize the stride of the data. Since the standard library doesn’t support reading strided data in any way, either you read the whole file, and then run a for loop creating objects from that data, or do whole reading in a for loop, skipping sizeof(int) after each object.