cmArgumentParser: Generalize internal state tracking

Use a `std::function` to support general actions on value arguments.

1 files changed, 9 insertions, 2 deletions

diff --git a/Source/cmArgumentParser.h b/Source/cmArgumentParser.h
index 33b8fff310..a417eb44ab 100644
--- a/Source/cmArgumentParser.h
+++ b/Source/cmArgumentParser.h
@@ -62,6 +62,12 @@ AsParseResultPtr(Result&)
   return nullptr;
 }
 
+enum class Continue
+{
+  No,
+  Yes,
+};
+
 class Instance;
 using KeywordAction = std::function<void(Instance&)>;
 using KeywordNameAction = std::function<void(Instance&, cm::string_view)>;
@@ -87,6 +93,7 @@ public:
 class Base
 {
 public:
+  using Continue = ArgumentParser::Continue;
   using Instance = ArgumentParser::Instance;
   using ParseResult = ArgumentParser::ParseResult;
 
@@ -129,6 +136,7 @@ public:
   {
   }
 
+  void Bind(std::function<Continue(cm::string_view)> f);
   void Bind(bool& val);
   void Bind(std::string& val);
   void Bind(Maybe<std::string>& val);
@@ -162,8 +170,7 @@ private:
   void* Result = nullptr;
 
   cm::string_view Keyword;
-  std::string* CurrentString = nullptr;
-  std::vector<std::string>* CurrentList = nullptr;
+  std::function<Continue(cm::string_view)> KeywordValueFunc;
   bool ExpectValue = false;
 
   void Consume(cm::string_view arg);