cmArgumentParser: Offer private binding to cmParseArgumentsCommand

The `keywordsMissingValue` argument to `Parse()` is now needed only for
the `cmake_parse_arguments` result `_KEYWORDS_MISSING_VALUES`.  Offer
its implementation a private binding for this.  Our internal clients can
use `ArgumentParser::NonEmpty<>` and friends to enforce the presence of
values.

1 files changed, 3 insertions, 0 deletions

diff --git a/Source/cmArgumentParser.cxx b/Source/cmArgumentParser.cxx
index 25d5c68..fcced96 100644
--- a/Source/cmArgumentParser.cxx
+++ b/Source/cmArgumentParser.cxx
@@ -116,6 +116,9 @@ void Instance::FinishKeyword()
     if (this->KeywordsMissingValue != nullptr) {
       this->KeywordsMissingValue->emplace_back(this->Keyword);
     }
+    if (this->Bindings.KeywordMissingValue) {
+      this->Bindings.KeywordMissingValue(*this, this->Keyword);
+    }
   }
 }