Revert "SERVER-30991 Introduce MatchExpression::optimize()."

This reverts commit 3cf4e0593c394dd7eb45d8000d76b5dc73a3f425.

Reverting because of a Clang compile error.

1 files changed, 0 insertions, 37 deletions

diff --git a/src/mongo/db/matcher/expression_leaf.cpp b/src/mongo/db/matcher/expression_leaf.cpp
index a1fc305b3cf..6a3502566e8 100644
--- a/src/mongo/db/matcher/expression_leaf.cpp
+++ b/src/mongo/db/matcher/expression_leaf.cpp
@@ -539,43 +539,6 @@ Status InMatchExpression::addRegex(std::unique_ptr<RegexMatchExpression> expr) {
     return Status::OK();
 }
 
-MatchExpression::ExpressionOptimizerFunc InMatchExpression::getOptimizer() const {
-    return [](std::unique_ptr<MatchExpression> expression) -> std::unique_ptr<MatchExpression> {
-        // NOTE: We do not recursively call optimize() on the RegexMatchExpression children in the
-        // _regexes list. We assume that optimize() on a RegexMatchExpression is a no-op.
-
-        auto& regexList = static_cast<InMatchExpression&>(*expression)._regexes;
-        auto& equalitySet = static_cast<InMatchExpression&>(*expression)._equalitySet;
-        auto collator = static_cast<InMatchExpression&>(*expression).getCollator();
-        if (regexList.size() == 1 && equalitySet.empty()) {
-            // Simplify IN of exactly one regex to be a regex match.
-            auto& childRe = regexList.front();
-            invariant(!childRe->getTag());
-
-            auto simplifiedExpression = stdx::make_unique<RegexMatchExpression>();
-            invariantOK(simplifiedExpression->init(
-                expression->path(), childRe->getString(), childRe->getFlags()));
-            if (expression->getTag()) {
-                simplifiedExpression->setTag(expression->getTag()->clone());
-            }
-
-            return simplifiedExpression;
-        } else if (equalitySet.size() == 1 && regexList.empty()) {
-            // Simplify IN of exactly one equality to be an EqualityMatchExpression.
-            auto simplifiedExpression = stdx::make_unique<EqualityMatchExpression>();
-            invariantOK(simplifiedExpression->init(expression->path(), *(equalitySet.begin())));
-            simplifiedExpression->setCollator(collator);
-            if (expression->getTag()) {
-                simplifiedExpression->setTag(expression->getTag()->clone());
-            }
-
-            return simplifiedExpression;
-        }
-
-        return expression;
-    };
-}
-
 // -----------
 
 Status BitTestMatchExpression::init(StringData path, std::vector<uint32_t> bitPositions) {