cmArgumentParser: Model maybe-empty and non-empty lists with wrapper types

Previously bindings to `std::vector<std::string>` required at least one
value.  Some clients have been filtering `keywordsMissingValue` to
support keywords followed by empty lists.  Instead, require clients to
specify whether a keyword's list can be empty as part of the binding
type.

1 files changed, 4 insertions, 3 deletions

diff --git a/Source/CTest/cmCTestSubmitCommand.h b/Source/CTest/cmCTestSubmitCommand.h
index 903bb64..b67f182 100644
--- a/Source/CTest/cmCTestSubmitCommand.h
+++ b/Source/CTest/cmCTestSubmitCommand.h
@@ -10,6 +10,7 @@
 
 #include <cm/optional>
 
+#include "cmArgumentParserTypes.h"
 #include "cmCTestHandlerCommand.h"
 
 class cmCommand;
@@ -50,7 +51,7 @@ protected:
   std::string RetryDelay;
   std::string SubmitURL;
 
-  cm::optional<std::vector<std::string>> Files;
-  std::vector<std::string> HttpHeaders;
-  cm::optional<std::vector<std::string>> Parts;
+  cm::optional<ArgumentParser::MaybeEmpty<std::vector<std::string>>> Files;
+  ArgumentParser::MaybeEmpty<std::vector<std::string>> HttpHeaders;
+  cm::optional<ArgumentParser::MaybeEmpty<std::vector<std::string>>> Parts;
 };