Question

I have an std::vector<unsigned char> with binary data in.

I just would like to simply read this vector, in a specific position with a specific size.

I would a function like this :

myvector.read(PositionBegin, Size)
myvector.read(1200,3)

This function could be read data from 1200, to 1203.

Is there a function like this in C++ ?

Answer 1

I’m assuming you want another std::vector with the range out…

This link provides a good answer: Best way to extract a subvector from a vector?

your function could look like:

std::vector<unsigned char> readFromVector(const std::vector<unsigned char> &myVec,
        unsigned start, unsigned len)
{
    // Replaced T with unsigned char (you could/should templatize...)
    std::vector<unsigned char>::const_iterator first = myVec.begin() + start;
    std::vector<unsigned char>::const_iterator last = first + len;
    std::vector<unsigned char> newVec(first, last);
    return newVec;
}