How do I write a range pipeline that uses temporary containers?

Question

I have a third-party function with this signature:

std::vector f(T t);

I also have an existing potentially infinite range (of the

Answer 1

It looks like there are now test cases in the range-v3 library that show how to do this correctly. It is necessary to add the views::cache1 operator into the pipeline:

auto rng = views::iota(0,4)
        | views::transform([](int i) {return std::string(i, char('a'+i));})
        | views::cache1
        | views::join('-');
check_equal(rng, {'-','b','-','c','c','-','d','d','d'});
CPP_assert(input_range);
CPP_assert(!range);
CPP_assert(!forward_range);
CPP_assert(!common_range);

so the solutions for the OP's question would be to write

auto rng = src | views::transform(f) | views::cache1 | views::join;