std::transform for a vector of vectors

c++, nested, range, transform, vector

Solution

What about the following, simply wrapping your `transform` in a `for_each`?

std::for_each( data.begin(), data.end(), 
               [&scalars](std::vector<double>& v) {
                  transform ( v.begin(), v.end(),
                              scalars.begin(),
                              v.begin(), plus<double>() );
                } 
             );

Problem

I have numerical data in a vector< vector < double> > and need to add scalar values to them as follows: ``` vector <vector<double> > data ( M, vector<double>(N) ); vector <double>scalars(N); data[0][0] += scalars[0]; data[0][1] += scalars[1]; ... data[0][N-1] += scalars[N-1]; data[1][0] += scalars[0]; data[1][1] += scalars[1]; ... data[1][N-1] += scalars[N-1]; ... data[M-1][N-1] += scalars[N-1]; ``` Of course this is possible with two for loops. I was wondering if it can be done as simply with transform, bind and plus? I'm trying to use functors where possible (although still use old C-style code out of habit). The inside loop would need to do this for the vector 0 in data: ``` transform ( data[0].begin(), data[0].end(), scalars[0].begin(), data[0].begin(), plus<double>() ) ``` Is it possible replace data[0] in this line with another counter (related to a transform on data[0]..data[N-1])? This is probably a standard problem but I could not find a good reference.

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