Function std::tensor_set_cols

void tensor_set_cols(&FloatTensor dst, unsigned long startCol, const &FloatTensor src)

Writes 'src' into 'dst's column range [startCol, startCol+numCols) (numCols == src's own column count), row by row, in place -- not part of the graph (tensor_concat_cols is the differentiable way to assemble columns).