Template trick to optimize out allocations

Question

I have:

struct DoubleVec {
  std::vector data;
};

DoubleVec operator+(const DoubleVec& lhs, const DoubleVec& rhs) {
  DoubleVec ans(lhs.si         


        

Answer 1

Have a look at Boost.Proto, which is a library for writing EDSL (embedded domain specific languages) directly in C++. There is even an example showing exactly what you need.