Question

My problem is, even though I use operator[] to get my vector contents, the vector is
calling always the size function (according to my profiling tool and time measurements).
So since my C++ application is very time critical (less than 0.1ms), i thought I’d better convert it into an array, but I couldn’t figure out so far.
The actual vector looks like:

std::vector<std::pair<double*,std::pair<double*,int*>>>

Answer 1

You can convert it to a pointer to the first element of an array like this:

pair<double *, pair<double *, int *> > *ar = &v[0];

Use v.data() instead of &v[0] in C++11.

Unrelatedly, I’m a little bit sceptical that the size() function is taking up a measureable amount of time. It’s usually an inline function that either returns a field or returns the difference of two pointer fields.