I think the bug did not describe the problem well, let me give it a shot. We want users to be able to say things like this:

auto results = table->ReadRows(bt::RowSet(
    "foo", "bar", bt::RowRange::left_open("a", "c"), bt::RowRange::right_open("f", l")));

that is, mix ranges (of different kinds), and single rows into a virtual collection. Those collections need to be mapped into the underlying google::bigtable::v2::RowSet protobuf.

Here is a propose list of operations to create RowRanges:

class RowRange {
public:
  //  unspecified stuff here, but basically ways to get to the beginning and end.
  // Create different types of ranges:
  static RowRange infinite_range();
  // an empty range
  Static RowRange empty();
  // the typical C++ range [begin,end)
  static RowRange right_open(std::string begin, std::string end);
  // a open interval (begin, end)
  static RowRange open_interval(std::string begin, std::string end);
  // a closed interval [begin, end]
  static RowRange closed_interval(std::string begin, std::string end);
  // a half-open interval (begin, end]
  static RowRange left_open(std::string begin, std::string end);
  // all the rows starting with @a prefix
  static RowRange prefix_range(std::string prefix);
  // an alias for right_open()
  static RowRange range(std::string begin, std::string end);
  // Some accessors
  bool contains(absl::string_view string) const;
  bool operator==(RowRange const&) const;
  bool operator!=(RowRange const& rhs) const { return !(*this == rhs); }
  // TODO(coryan) - maybe other operators, remember std::rel_ops<>
  // the intersection of two ranges (useful for retries)
  static RowRange intersect(RowRange const& lhs, RowRange const& rhs);
};

class RowSet { public:
  template<typename... Args>
  RowSet(Args&&... k) {
    // call Add() for each "k" in the parameter pack
  }

  // And a key or range
  RowSet& Add(std::string rowkey);
  RowSet& Add(absl::string_view rowkey);
  RowSet& Add(RowRange range);
};

The questions to figure out are:

How is that constructor with the parameter pack implemented (it should not be hard in C++17, but we are sticking to C++11)
How does this map into the protobuf? Is there a Export() member function that takes the protobuf as an in/out argument? Does it return a protobuf? Or a MoveTo() member function that destructively moves into the protobuf parameter?

Write down design doc for Row Range and Row Set wrappers #31

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