SERVER-23882 Collation should be considered part of a query's shape

2 files changed, 19 insertions, 16 deletions

diff --git a/src/mongo/db/matcher/expression_algo.cpp b/src/mongo/db/matcher/expression_algo.cpp
index 6365d3326bb..d918ead80f9 100644
--- a/src/mongo/db/matcher/expression_algo.cpp
+++ b/src/mongo/db/matcher/expression_algo.cpp
@@ -46,19 +46,6 @@ using std::unique_ptr;
 
 namespace {
 
-bool isComparisonMatchExpression(const MatchExpression* expr) {
-    switch (expr->matchType()) {
-        case MatchExpression::LT:
-        case MatchExpression::LTE:
-        case MatchExpression::EQ:
-        case MatchExpression::GTE:
-        case MatchExpression::GT:
-            return true;
-        default:
-            return false;
-    }
-}
-
 bool supportsEquality(const ComparisonMatchExpression* expr) {
     switch (expr->matchType()) {
         case MatchExpression::LTE:
@@ -153,7 +140,7 @@ bool _isSubsetOf(const MatchExpression* lhs, const ComparisonMatchExpression* rh
         return false;
     }
 
-    if (isComparisonMatchExpression(lhs)) {
+    if (ComparisonMatchExpression::isComparisonMatchExpression(lhs)) {
         return _isSubsetOf(static_cast<const ComparisonMatchExpression*>(lhs), rhs);
     }
 
@@ -188,7 +175,7 @@ bool _isSubsetOf(const MatchExpression* lhs, const ExistsMatchExpression* rhs) {
         return false;
     }
 
-    if (isComparisonMatchExpression(lhs)) {
+    if (ComparisonMatchExpression::isComparisonMatchExpression(lhs)) {
         const ComparisonMatchExpression* cme = static_cast<const ComparisonMatchExpression*>(lhs);
         // CompareMatchExpression::init() prohibits creating a match expression with EOO or
         // Undefined types, so only need to ensure that the value is not of type jstNULL.
@@ -338,7 +325,7 @@ bool isSubsetOf(const MatchExpression* lhs, const MatchExpression* rhs) {
         return true;
     }
 
-    if (isComparisonMatchExpression(rhs)) {
+    if (ComparisonMatchExpression::isComparisonMatchExpression(rhs)) {
         return _isSubsetOf(lhs, static_cast<const ComparisonMatchExpression*>(rhs));
     }
 
diff --git a/src/mongo/db/matcher/expression_leaf.h b/src/mongo/db/matcher/expression_leaf.h
index 7ef4dd7c860..62a45c81e9c 100644
--- a/src/mongo/db/matcher/expression_leaf.h
+++ b/src/mongo/db/matcher/expression_leaf.h
@@ -117,6 +117,22 @@ public:
         return _collator;
     }
 
+    /**
+     * Returns true if the MatchExpression is a ComparisonMatchExpression.
+     */
+    static bool isComparisonMatchExpression(const MatchExpression* expr) {
+        switch (expr->matchType()) {
+            case MatchExpression::LT:
+            case MatchExpression::LTE:
+            case MatchExpression::EQ:
+            case MatchExpression::GTE:
+            case MatchExpression::GT:
+                return true;
+            default:
+                return false;
+        }
+    }
+
 protected:
     BSONElement _rhs;