MATLAB's linspace in C++

linspace.cpp

template <typename T = double>
vector<T> linspace(T a, T b, size_t N) {
  T h = (b - a) / static_cast<T>(N-1);
  vector<T> xs(N);
  typename vector<T>::iterator x;
  T val;
  for (x = xs.begin(), val = a; x != xs.end(); ++x, val += h)
    *x = val;
  return xs;
}

Repeated addition of floating point numbers can be numerically unstable. It might instead be better to use a method similar to numpy.linspace, available at https://github.com/numpy/numpy/blob/master/numpy/core/function_base.py

A simple addition would be to set xs.back()=b, if the issue pointed out by @garrison is not a problem.