How to get the index of a value in a vector using for_each?

Question

I have the following code (compiler: MSVC++ 10):

std::vector data;
data.push_back(1.0f);
data.push_back(1.0f);
data.push_back(2.0f);

// lambda          


        

Answer 1

Alternatively, you can use &value - &data[0], although it might be a bit more expensive.

std::for_each(data.begin(), data.end(), [&data](float const& value) {
    int idx = &value - &data[0];
});