c++ - How to copy a certain number of chars from a file to a vector the STL-way?

Question

If I want to copy the contents of a file to a vector, I can do it like that:

std::ifstream file("path_to_file");
std::vector<char> buffer(std::istream_iterator<char>(file), 
                         std::istream_iterator<char>());

My question is, how would I do this if I want to copy only the first n chars?

Edit I could write my own version of copy, but is there a way to do this using only existing components?

Answer 1

As Alexander points out, the fastest way would be

std::vector<char> buffer(n);
file.read(&buffer[0], n);

In C++0x, you can use buffer.data() instead of &buffer[0]; the latter has undefined behavior if n == 0.