SERVER-40476 remove mongoutils::str::equals

29 files changed, 125 insertions, 127 deletions

diff --git a/src/mongo/db/catalog/index_key_validate.cpp b/src/mongo/db/catalog/index_key_validate.cpp
index 1927e0c74ae..c63f2530d20 100644
--- a/src/mongo/db/catalog/index_key_validate.cpp
+++ b/src/mongo/db/catalog/index_key_validate.cpp
@@ -199,11 +199,11 @@ Status validateKeyPattern(const BSONObj& key, IndexDescriptor::IndexVersion inde
         }
 
         // "$**" is acceptable for a text index or wildcard index.
-        if (mongoutils::str::equals(keyElement.fieldName(), "$**") &&
+        if ((keyElement.fieldNameStringData() == "$**") &&
             ((keyElement.isNumber()) || (keyElement.valuestrsafe() == IndexNames::TEXT)))
             continue;
 
-        if (mongoutils::str::equals(keyElement.fieldName(), "_fts") &&
+        if ((keyElement.fieldNameStringData() == "_fts") &&
             keyElement.valuestrsafe() != IndexNames::TEXT) {
             return Status(code, "Index key contains an illegal field name: '_fts'");
         }
diff --git a/src/mongo/db/commands/list_collections.cpp b/src/mongo/db/commands/list_collections.cpp
index 9080535db4a..1ddf5820be2 100644
--- a/src/mongo/db/commands/list_collections.cpp
+++ b/src/mongo/db/commands/list_collections.cpp
@@ -90,7 +90,7 @@ boost::optional<vector<StringData>> _getExactNameMatches(const MatchExpression*
     if (matchType == MatchExpression::EQ) {
         auto eqMatch = checked_cast<const EqualityMatchExpression*>(matcher);
         if (eqMatch->path() == "name") {
-            StringData name(eqMatch->getData().valuestrsafe());
+            StringData name(eqMatch->getData().valueStringDataSafe());
             if (name.size()) {
                 return {vector<StringData>{name}};
             } else {
@@ -102,7 +102,7 @@ boost::optional<vector<StringData>> _getExactNameMatches(const MatchExpression*
         if (matchIn->path() == "name" && matchIn->getRegexes().empty()) {
             vector<StringData> exactMatches;
             for (auto&& elem : matchIn->getEqualities()) {
-                StringData name(elem.valuestrsafe());
+                StringData name(elem.valueStringDataSafe());
                 if (name.size()) {
                     exactMatches.push_back(elem.valueStringData());
                 }
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index 217db0ed3d5..99dacfecbfa 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -558,7 +558,7 @@ void State::prepTempCollection() {
                 BSONObjIterator j(currIndex->infoObj());
                 while (j.more()) {
                     BSONElement e = j.next();
-                    if (str::equals(e.fieldName(), "_id") || str::equals(e.fieldName(), "ns"))
+                    if (e.fieldNameStringData() == "_id" || e.fieldNameStringData() == "ns")
                         continue;
                     b.append(e);
                 }
diff --git a/src/mongo/db/exec/projection.cpp b/src/mongo/db/exec/projection.cpp
index 2b8984ead68..33ecf709de9 100644
--- a/src/mongo/db/exec/projection.cpp
+++ b/src/mongo/db/exec/projection.cpp
@@ -136,7 +136,7 @@ void ProjectionStage::getSimpleInclusionFields(const BSONObj& projObj, FieldSet*
         BSONElement elt = projObjIt.next();
         // Must deal with the _id case separately as there is an implicit _id: 1 in the
         // projection.
-        if (mongoutils::str::equals(elt.fieldName(), kIdField) && !elt.trueValue()) {
+        if ((elt.fieldNameStringData() == kIdField) && !elt.trueValue()) {
             includeId = false;
             continue;
         }
diff --git a/src/mongo/db/exec/projection_exec.cpp b/src/mongo/db/exec/projection_exec.cpp
index f30eedaf6d8..987ce85252b 100644
--- a/src/mongo/db/exec/projection_exec.cpp
+++ b/src/mongo/db/exec/projection_exec.cpp
@@ -61,7 +61,7 @@ ProjectionExec::ProjectionExec(OperationContext* opCtx,
             invariant(1 == obj.nFields());
 
             BSONElement e2 = obj.firstElement();
-            if (mongoutils::str::equals(e2.fieldName(), "$slice")) {
+            if (e2.fieldNameStringData() == "$slice") {
                 if (e2.isNumber()) {
                     int i = e2.numberInt();
                     if (i < 0) {
@@ -82,7 +82,7 @@ ProjectionExec::ProjectionExec(OperationContext* opCtx,
 
                     add(e.fieldName(), skip, limit);
                 }
-            } else if (mongoutils::str::equals(e2.fieldName(), "$elemMatch")) {
+            } else if (e2.fieldNameStringData() == "$elemMatch") {
                 _arrayOpType = ARRAY_OP_ELEM_MATCH;
 
                 // Create a MatchExpression for the elemMatch.
@@ -99,7 +99,7 @@ ProjectionExec::ProjectionExec(OperationContext* opCtx,
                     statusWithMatcher.getValue().release();
 
                 add(e.fieldName(), true);
-            } else if (mongoutils::str::equals(e2.fieldName(), "$meta")) {
+            } else if (e2.fieldNameStringData() == "$meta") {
                 invariant(String == e2.type());
                 if (e2.valuestr() == QueryRequest::metaTextScore) {
                     _meta[e.fieldName()] = META_TEXT_SCORE;
@@ -125,7 +125,7 @@ ProjectionExec::ProjectionExec(OperationContext* opCtx,
             } else {
                 MONGO_UNREACHABLE;
             }
-        } else if (mongoutils::str::equals(e.fieldName(), "_id") && !e.trueValue()) {
+        } else if ((e.fieldNameStringData() == "_id") && !e.trueValue()) {
             _includeID = false;
         } else {
             add(e.fieldName(), e.trueValue());
@@ -258,7 +258,7 @@ StatusWith<BSONObj> ProjectionExec::projectCovered(const std::vector<IndexKeyDat
     mmb::Document projectedDoc;
 
     for (auto&& specElt : _source) {
-        if (mongoutils::str::equals("_id", specElt.fieldName())) {
+        if (specElt.fieldNameStringData() == "_id") {
             continue;
         }
 
@@ -340,7 +340,7 @@ Status ProjectionExec::projectHelper(const BSONObj& in,
         BSONElement elt = it.next();
 
         // Case 1: _id
-        if (mongoutils::str::equals("_id", elt.fieldName())) {
+        if ("_id" == elt.fieldNameStringData()) {
             if (_includeID) {
                 bob->append(elt);
             }
diff --git a/src/mongo/db/fts/fts_spec.cpp b/src/mongo/db/fts/fts_spec.cpp
index 49271fa99df..14bb7b8bfdc 100644
--- a/src/mongo/db/fts/fts_spec.cpp
+++ b/src/mongo/db/fts/fts_spec.cpp
@@ -147,7 +147,7 @@ FTSSpec::FTSSpec(const BSONObj& indexInfo) {
 
         while (i.more()) {
             BSONElement e = i.next();
-            if (str::equals(e.fieldName(), "_fts") || str::equals(e.fieldName(), "_ftsx")) {
+            if ((e.fieldNameStringData() == "_fts") || (e.fieldNameStringData() == "_ftsx")) {
                 passedFTS = true;
                 continue;
             }
@@ -293,13 +293,13 @@ StatusWith<BSONObj> FTSSpec::fixSpec(const BSONObj& spec) {
             BSONObjIterator i(spec["key"].Obj());
             while (i.more()) {
                 BSONElement e = i.next();
-                if (str::equals(e.fieldName(), "_fts")) {
+                if (e.fieldNameStringData() == "_fts") {
                     if (INDEX_NAME != e.valuestrsafe()) {
                         return {ErrorCodes::CannotCreateIndex, "expecting _fts:\"text\""};
                     }
                     addedFtsStuff = true;
                     b.append(e);
-                } else if (str::equals(e.fieldName(), "_ftsx")) {
+                } else if (e.fieldNameStringData() == "_ftsx") {
                     if (e.numberInt() != 1) {
                         return {ErrorCodes::CannotCreateIndex, "expecting _ftsx:1"};
                     }
@@ -346,13 +346,13 @@ StatusWith<BSONObj> FTSSpec::fixSpec(const BSONObj& spec) {
             }
 
             // text fields
-            bool alreadyFixed = str::equals(e.fieldName(), "_fts");
+            bool alreadyFixed = (e.fieldNameStringData() == "_fts");
             if (alreadyFixed) {
                 if (!i.more()) {
                     return {ErrorCodes::CannotCreateIndex, "expected _ftsx after _fts"};
                 }
                 e = i.next();
-                if (!str::equals(e.fieldName(), "_ftsx")) {
+                if (e.fieldNameStringData() != "_ftsx") {
                     return {ErrorCodes::CannotCreateIndex, "expected _ftsx after _fts"};
                 }
                 e = i.next();
@@ -468,20 +468,21 @@ StatusWith<BSONObj> FTSSpec::fixSpec(const BSONObj& spec) {
     BSONObjIterator i(spec);
     while (i.more()) {
         BSONElement e = i.next();
-        if (str::equals(e.fieldName(), "key")) {
+        StringData fieldName = e.fieldNameStringData();
+        if (fieldName == "key") {
             b.append("key", keyPattern);
-        } else if (str::equals(e.fieldName(), "weights")) {
+        } else if (fieldName == "weights") {
             b.append("weights", weights);
             weights = BSONObj();
-        } else if (str::equals(e.fieldName(), "default_language")) {
+        } else if (fieldName == "default_language") {
             b.append("default_language", default_language);
             default_language = "";
-        } else if (str::equals(e.fieldName(), "language_override")) {
+        } else if (fieldName == "language_override") {
             b.append("language_override", language_override);
             language_override = "";
-        } else if (str::equals(e.fieldName(), "v")) {
+        } else if (fieldName == "v") {
             version = e.numberInt();
-        } else if (str::equals(e.fieldName(), "textIndexVersion")) {
+        } else if (fieldName == "textIndexVersion") {
             if (!e.isNumber()) {
                 return {ErrorCodes::CannotCreateIndex,
                         "text index option 'textIndexVersion' must be a number"};
diff --git a/src/mongo/db/fts/fts_spec_legacy.cpp b/src/mongo/db/fts/fts_spec_legacy.cpp
index f1e244c616e..dcb7357166b 100644
--- a/src/mongo/db/fts/fts_spec_legacy.cpp
+++ b/src/mongo/db/fts/fts_spec_legacy.cpp
@@ -206,11 +206,11 @@ StatusWith<BSONObj> FTSSpec::_fixSpecV1(const BSONObj& spec) {
         BSONObjIterator i(spec["key"].Obj());
         while (i.more()) {
             BSONElement e = i.next();
-            if (str::equals(e.fieldName(), "_fts") || str::equals(e.fieldName(), "_ftsx")) {
+            if ((e.fieldNameStringData() == "_fts") || (e.fieldNameStringData() == "_ftsx")) {
                 addedFtsStuff = true;
                 b.append(e);
             } else if (e.type() == String &&
-                       (str::equals("fts", e.valuestr()) || str::equals("text", e.valuestr()))) {
+                       (e.valueStringData() == "fts" || e.valueStringData() == "text")) {
                 if (!addedFtsStuff) {
                     _addFTSStuff(&b);
                     addedFtsStuff = true;
@@ -269,20 +269,21 @@ StatusWith<BSONObj> FTSSpec::_fixSpecV1(const BSONObj& spec) {
     BSONObjIterator i(spec);
     while (i.more()) {
         BSONElement e = i.next();
-        if (str::equals(e.fieldName(), "key")) {
+        StringData fieldName = e.fieldNameStringData();
+        if (fieldName == "key") {
             b.append("key", keyPattern);
-        } else if (str::equals(e.fieldName(), "weights")) {
+        } else if (fieldName == "weights") {
             b.append("weights", weights);
             weights = BSONObj();
-        } else if (str::equals(e.fieldName(), "default_language")) {
+        } else if (fieldName == "default_language") {
             b.append("default_language", default_language);
             default_language = "";
-        } else if (str::equals(e.fieldName(), "language_override")) {
+        } else if (fieldName == "language_override") {
             b.append("language_override", language_override);
             language_override = "";
-        } else if (str::equals(e.fieldName(), "v")) {
+        } else if (fieldName == "v") {
             version = e.numberInt();
-        } else if (str::equals(e.fieldName(), "textIndexVersion")) {
+        } else if (fieldName == "textIndexVersion") {
             textIndexVersion = e.numberInt();
             if (textIndexVersion != 1) {
                 return {ErrorCodes::CannotCreateIndex,
diff --git a/src/mongo/db/geo/geometry_container.cpp b/src/mongo/db/geo/geometry_container.cpp
index 2d529afd8aa..bea64bf8f0f 100644
--- a/src/mongo/db/geo/geometry_container.cpp
+++ b/src/mongo/db/geo/geometry_container.cpp
@@ -36,8 +36,6 @@
 
 namespace mongo {
 
-using mongoutils::str::equals;
-
 bool GeometryContainer::isSimpleContainer() const {
     return NULL != _point || NULL != _line || NULL != _polygon;
 }
diff --git a/src/mongo/db/geo/geoparser.cpp b/src/mongo/db/geo/geoparser.cpp
index 4156f4d7b77..c5a723805b2 100644
--- a/src/mongo/db/geo/geoparser.cpp
+++ b/src/mongo/db/geo/geoparser.cpp
@@ -776,16 +776,16 @@ GeoParser::GeoSpecifier GeoParser::parseGeoSpecifier(const BSONElement& type) {
     if (!type.isABSONObj()) {
         return GeoParser::UNKNOWN;
     }
-    const char* fieldName = type.fieldName();
-    if (mongoutils::str::equals(fieldName, "$box")) {
+    StringData fieldName = type.fieldNameStringData();
+    if (fieldName == "$box") {
         return GeoParser::BOX;
-    } else if (mongoutils::str::equals(fieldName, "$center")) {
+    } else if (fieldName == "$center") {
         return GeoParser::CENTER;
-    } else if (mongoutils::str::equals(fieldName, "$polygon")) {
+    } else if (fieldName == "$polygon") {
         return GeoParser::POLYGON;
-    } else if (mongoutils::str::equals(fieldName, "$centerSphere")) {
+    } else if (fieldName == "$centerSphere") {
         return GeoParser::CENTER_SPHERE;
-    } else if (mongoutils::str::equals(fieldName, "$geometry")) {
+    } else if (fieldName == "$geometry") {
         return GeoParser::GEOMETRY;
     }
     return GeoParser::UNKNOWN;
diff --git a/src/mongo/db/keypattern.cpp b/src/mongo/db/keypattern.cpp
index f0cb5df21dc..67fd8b08460 100644
--- a/src/mongo/db/keypattern.cpp
+++ b/src/mongo/db/keypattern.cpp
@@ -98,7 +98,7 @@ BSONObj KeyPattern::extendRangeBound(const BSONObj& bound, bool makeUpperInclusi
                 str::stream() << "field names of bound " << bound
                               << " do not match those of keyPattern "
                               << _pattern,
-                str::equals(srcElt.fieldName(), patElt.fieldName()));
+                srcElt.fieldNameStringData() == patElt.fieldNameStringData());
         newBound.append(srcElt);
     }
     while (pat.more()) {
diff --git a/src/mongo/db/matcher/expression_geo.cpp b/src/mongo/db/matcher/expression_geo.cpp
index b25ee5cf19e..34596d34c45 100644
--- a/src/mongo/db/matcher/expression_geo.cpp
+++ b/src/mongo/db/matcher/expression_geo.cpp
@@ -40,9 +40,6 @@
 
 namespace mongo {
 
-
-using mongoutils::str::equals;
-
 //
 // GeoExpression
 //
@@ -80,7 +77,7 @@ Status GeoExpression::parseQuery(const BSONObj& obj) {
 
     while (geoIt.more()) {
         BSONElement elt = geoIt.next();
-        if (str::equals(elt.fieldName(), "$uniqueDocs")) {
+        if (elt.fieldNameStringData() == "$uniqueDocs") {
             // Deprecated "$uniqueDocs" field
             warning() << "deprecated $uniqueDocs option: " << redact(obj);
         } else {
@@ -175,8 +172,8 @@ bool GeoNearExpression::parseLegacyQuery(const BSONObj& obj) {
     BSONObjIterator it(obj);
     while (it.more()) {
         BSONElement e = it.next();
-        if (equals(e.fieldName(), "$near") || equals(e.fieldName(), "$geoNear") ||
-            equals(e.fieldName(), "$nearSphere")) {
+        StringData fieldName = e.fieldNameStringData();
+        if ((fieldName == "$near") || (fieldName == "$geoNear") || (fieldName == "$nearSphere")) {
             if (!e.isABSONObj()) {
                 return false;
             }
@@ -186,17 +183,17 @@ bool GeoNearExpression::parseLegacyQuery(const BSONObj& obj) {
                 GeoParser::parsePointWithMaxDistance(embeddedObj, centroid.get(), &maxDistance)) {
                 uassert(18522, "max distance must be non-negative", maxDistance >= 0.0);
                 hasGeometry = true;
-                isNearSphere = equals(e.fieldName(), "$nearSphere");
+                isNearSphere = (e.fieldNameStringData() == "$nearSphere");
             }
-        } else if (equals(e.fieldName(), "$minDistance")) {
+        } else if (fieldName == "$minDistance") {
             uassert(16893, "$minDistance must be a number", e.isNumber());
             minDistance = e.Number();
             uassert(16894, "$minDistance must be non-negative", minDistance >= 0.0);
-        } else if (equals(e.fieldName(), "$maxDistance")) {
+        } else if (fieldName == "$maxDistance") {
             uassert(16895, "$maxDistance must be a number", e.isNumber());
             maxDistance = e.Number();
             uassert(16896, "$maxDistance must be non-negative", maxDistance >= 0.0);
-        } else if (equals(e.fieldName(), "$uniqueDocs")) {
+        } else if (fieldName == "$uniqueDocs") {
             warning() << "ignoring deprecated option $uniqueDocs";
         } else {
             // In a query document, $near queries can have no non-geo sibling parameters.
@@ -242,7 +239,8 @@ Status GeoNearExpression::parseNewQuery(const BSONObj& obj) {
     BSONObjIterator it(e.embeddedObject());
     while (it.more()) {
         BSONElement e = it.next();
-        if (equals(e.fieldName(), "$geometry")) {
+        StringData fieldName = e.fieldNameStringData();
+        if (fieldName == "$geometry") {
             if (e.isABSONObj()) {
                 BSONObj embeddedObj = e.embeddedObject();
                 Status status = GeoParser::parseQueryPoint(e, centroid.get());
@@ -259,11 +257,11 @@ Status GeoNearExpression::parseNewQuery(const BSONObj& obj) {
                         (SPHERE == centroid->crs));
                 hasGeometry = true;
             }
-        } else if (equals(e.fieldName(), "$minDistance")) {
+        } else if (fieldName == "$minDistance") {
             uassert(16897, "$minDistance must be a number", e.isNumber());
             minDistance = e.Number();
             uassert(16898, "$minDistance must be non-negative", minDistance >= 0.0);
-        } else if (equals(e.fieldName(), "$maxDistance")) {
+        } else if (fieldName == "$maxDistance") {
             uassert(16899, "$maxDistance must be a number", e.isNumber());
             maxDistance = e.Number();
             uassert(16900, "$maxDistance must be non-negative", maxDistance >= 0.0);
diff --git a/src/mongo/db/pipeline/document_source_group.cpp b/src/mongo/db/pipeline/document_source_group.cpp
index fa006b78b0c..9625bc65d97 100644
--- a/src/mongo/db/pipeline/document_source_group.cpp
+++ b/src/mongo/db/pipeline/document_source_group.cpp
@@ -396,14 +396,14 @@ intrusive_ptr<DocumentSource> DocumentSourceGroup::createFromBson(
     VariablesParseState vps = pExpCtx->variablesParseState;
     while (groupIterator.more()) {
         BSONElement groupField(groupIterator.next());
-        const char* pFieldName = groupField.fieldName();
+        StringData pFieldName = groupField.fieldNameStringData();
 
-        if (str::equals(pFieldName, "_id")) {
+        if (pFieldName == "_id") {
             uassert(
                 15948, "a group's _id may only be specified once", pGroup->_idExpressions.empty());
             pGroup->setIdExpression(parseIdExpression(pExpCtx, groupField, vps));
             invariant(!pGroup->_idExpressions.empty());
-        } else if (str::equals(pFieldName, "$doingMerge")) {
+        } else if (pFieldName == "$doingMerge") {
             massert(17030, "$doingMerge should be true if present", groupField.Bool());
 
             pGroup->setDoingMerge(true);
diff --git a/src/mongo/db/pipeline/document_source_match.cpp b/src/mongo/db/pipeline/document_source_match.cpp
index 7cb3bcec620..0a269db2451 100644
--- a/src/mongo/db/pipeline/document_source_match.cpp
+++ b/src/mongo/db/pipeline/document_source_match.cpp
@@ -298,9 +298,10 @@ Document redactSafePortionDollarOps(BSONObj expr) {
 // the expression can safely be promoted in front of a $redact.
 Document redactSafePortionTopLevel(BSONObj query) {
     MutableDocument output;
-    BSONForEach(field, query) {
-        if (field.fieldName()[0] == '$') {
-            if (str::equals(field.fieldName(), "$or")) {
+    for (BSONElement field : query) {
+        StringData fieldName = field.fieldNameStringData();
+        if (fieldName.startsWith("$")) {
+            if (fieldName == "$or") {
                 // $or must be all-or-nothing (line $in). Can't include subset of elements.
                 vector<Value> okClauses;
                 BSONForEach(elem, field.Obj()) {
@@ -314,7 +315,7 @@ Document redactSafePortionTopLevel(BSONObj query) {
 
                 if (!okClauses.empty())
                     output["$or"] = Value(std::move(okClauses));
-            } else if (str::equals(field.fieldName(), "$and")) {
+            } else if (fieldName == "$and") {
                 // $and can include subset of elements (like $all).
                 vector<Value> okClauses;
                 BSONForEach(elem, field.Obj()) {
@@ -356,7 +357,7 @@ Document redactSafePortionTopLevel(BSONObj query) {
     }
     return output.freeze();
 }
-}
+}  // namespace
 
 BSONObj DocumentSourceMatch::redactSafePortion() const {
     return redactSafePortionTopLevel(getQuery()).toBson();
diff --git a/src/mongo/db/pipeline/expression.cpp b/src/mongo/db/pipeline/expression.cpp
index d61854b3ba3..864ca057945 100644
--- a/src/mongo/db/pipeline/expression.cpp
+++ b/src/mongo/db/pipeline/expression.cpp
@@ -906,18 +906,18 @@ intrusive_ptr<Expression> ExpressionCond::parse(
     if (expr.type() != Object) {
         return Base::parse(expCtx, expr, vps);
     }
-    verify(str::equals(expr.fieldName(), "$cond"));
+    verify(expr.fieldNameStringData() == "$cond");
 
     intrusive_ptr<ExpressionCond> ret = new ExpressionCond(expCtx);
     ret->vpOperand.resize(3);
 
     const BSONObj args = expr.embeddedObject();
     BSONForEach(arg, args) {
-        if (str::equals(arg.fieldName(), "if")) {
+        if (arg.fieldNameStringData() == "if") {
             ret->vpOperand[0] = parseOperand(expCtx, arg, vps);
-        } else if (str::equals(arg.fieldName(), "then")) {
+        } else if (arg.fieldNameStringData() == "then") {
             ret->vpOperand[1] = parseOperand(expCtx, arg, vps);
-        } else if (str::equals(arg.fieldName(), "else")) {
+        } else if (arg.fieldNameStringData() == "else") {
             ret->vpOperand[2] = parseOperand(expCtx, arg, vps);
         } else {
             uasserted(17083,
@@ -1640,7 +1640,7 @@ intrusive_ptr<Expression> ExpressionDateToString::parse(
     const boost::intrusive_ptr<ExpressionContext>& expCtx,
     BSONElement expr,
     const VariablesParseState& vps) {
-    verify(str::equals(expr.fieldName(), "$dateToString"));
+    verify(expr.fieldNameStringData() == "$dateToString");
 
     uassert(18629,
             "$dateToString only supports an object as its argument",
@@ -2110,7 +2110,7 @@ intrusive_ptr<Expression> ExpressionFilter::parse(
     const boost::intrusive_ptr<ExpressionContext>& expCtx,
     BSONElement expr,
     const VariablesParseState& vpsIn) {
-    verify(str::equals(expr.fieldName(), "$filter"));
+    verify(expr.fieldNameStringData() == "$filter");
 
     uassert(28646, "$filter only supports an object as its argument", expr.type() == Object);
 
@@ -2119,11 +2119,11 @@ intrusive_ptr<Expression> ExpressionFilter::parse(
     BSONElement asElem;
     BSONElement condElem;
     for (auto elem : expr.Obj()) {
-        if (str::equals(elem.fieldName(), "input")) {
+        if (elem.fieldNameStringData() == "input") {
             inputElem = elem;
-        } else if (str::equals(elem.fieldName(), "as")) {
+        } else if (elem.fieldNameStringData() == "as") {
             asElem = elem;
-        } else if (str::equals(elem.fieldName(), "cond")) {
+        } else if (elem.fieldNameStringData() == "cond") {
             condElem = elem;
         } else {
             uasserted(28647,
@@ -2239,7 +2239,7 @@ intrusive_ptr<Expression> ExpressionLet::parse(
     const boost::intrusive_ptr<ExpressionContext>& expCtx,
     BSONElement expr,
     const VariablesParseState& vpsIn) {
-    verify(str::equals(expr.fieldName(), "$let"));
+    verify(expr.fieldNameStringData() == "$let");
 
     uassert(16874, "$let only supports an object as its argument", expr.type() == Object);
     const BSONObj args = expr.embeddedObject();
@@ -2248,9 +2248,9 @@ intrusive_ptr<Expression> ExpressionLet::parse(
     BSONElement varsElem;
     BSONElement inElem;
     BSONForEach(arg, args) {
-        if (str::equals(arg.fieldName(), "vars")) {
+        if (arg.fieldNameStringData() == "vars") {
             varsElem = arg;
-        } else if (str::equals(arg.fieldName(), "in")) {
+        } else if (arg.fieldNameStringData() == "in") {
             inElem = arg;
         } else {
             uasserted(16875,
@@ -2338,7 +2338,7 @@ intrusive_ptr<Expression> ExpressionMap::parse(
     const boost::intrusive_ptr<ExpressionContext>& expCtx,
     BSONElement expr,
     const VariablesParseState& vpsIn) {
-    verify(str::equals(expr.fieldName(), "$map"));
+    verify(expr.fieldNameStringData() == "$map");
 
     uassert(16878, "$map only supports an object as its argument", expr.type() == Object);
 
@@ -2348,11 +2348,11 @@ intrusive_ptr<Expression> ExpressionMap::parse(
     BSONElement inElem;
     const BSONObj args = expr.embeddedObject();
     BSONForEach(arg, args) {
-        if (str::equals(arg.fieldName(), "input")) {
+        if (arg.fieldNameStringData() == "input") {
             inputElem = arg;
-        } else if (str::equals(arg.fieldName(), "as")) {
+        } else if (arg.fieldNameStringData() == "as") {
             asElem = arg;
-        } else if (str::equals(arg.fieldName(), "in")) {
+        } else if (arg.fieldNameStringData() == "in") {
             inElem = arg;
         } else {
             uasserted(16879,
@@ -3113,7 +3113,7 @@ intrusive_ptr<Expression> ExpressionNary::optimize() {
             // is also associative, replace the expression for the operands it has.
             // E.g: sum(a, b, sum(c, d), e) => sum(a, b, c, d, e)
             ExpressionNary* nary = dynamic_cast<ExpressionNary*>(operand.get());
-            if (nary && str::equals(nary->getOpName(), getOpName()) && nary->isAssociative()) {
+            if (nary && !strcmp(nary->getOpName(), getOpName()) && nary->isAssociative()) {
                 invariant(!nary->vpOperand.empty());
                 vpOperand[i] = std::move(nary->vpOperand[0]);
                 vpOperand.insert(
diff --git a/src/mongo/db/pipeline/expression_test.cpp b/src/mongo/db/pipeline/expression_test.cpp
index 5c2426217ab..62695188828 100644
--- a/src/mongo/db/pipeline/expression_test.cpp
+++ b/src/mongo/db/pipeline/expression_test.cpp
@@ -113,8 +113,8 @@ static BSONObj constify(const BSONObj& obj, bool parentIsArray = false) {
             // arrays within arrays are treated as constant values by the real
             // parser
             bob << elem.fieldName() << BSONArray(constify(elem.Obj(), true));
-        } else if (str::equals(elem.fieldName(), "$const") ||
-                   (elem.type() == mongo::String && elem.valuestrsafe()[0] == '$')) {
+        } else if (elem.fieldNameStringData() == "$const" ||
+                   (elem.type() == mongo::String && elem.valueStringDataSafe().startsWith("$"))) {
             bob.append(elem);
         } else {
             bob.append(elem.fieldName(), BSON("$const" << elem));
diff --git a/src/mongo/db/query/canonical_query.cpp b/src/mongo/db/query/canonical_query.cpp
index cf6fb23c661..0be2f524798 100644
--- a/src/mongo/db/query/canonical_query.cpp
+++ b/src/mongo/db/query/canonical_query.cpp
@@ -270,7 +270,7 @@ bool CanonicalQuery::isSimpleIdQuery(const BSONObj& query) {
     BSONObjIterator it(query);
     while (it.more()) {
         BSONElement elt = it.next();
-        if (str::equals("_id", elt.fieldName())) {
+        if (elt.fieldNameStringData() == "_id") {
             // Verify that the query on _id is a simple equality.
             hasID = true;
 
diff --git a/src/mongo/db/query/collation/collator_factory_icu.cpp b/src/mongo/db/query/collation/collator_factory_icu.cpp
index 5c891e02c4c..8c232d60025 100644
--- a/src/mongo/db/query/collation/collator_factory_icu.cpp
+++ b/src/mongo/db/query/collation/collator_factory_icu.cpp
@@ -46,7 +46,7 @@ namespace mongo {
 
 namespace {
 
-const char kFallbackLocaleName[] = "root";
+constexpr StringData kFallbackLocaleName = "root"_sd;
 
 // Helper methods for converting between ICU attributes and types used by CollationSpec.
 
@@ -646,13 +646,12 @@ Status validateLocaleID(const BSONObj& spec,
     // resulting icu::Locale name will not match the requested locale. In this case we return an
     // error to the user. In the error message to the user, we report the locale that ICU *would
     // have* used, which the application can supply as an alternative.
-    const char* collatorLocaleName = collatorLocale.getName();
-    if (StringData(originalID) != StringData(collatorLocaleName)) {
+    auto collatorLocaleName = StringData(collatorLocale.getName());
+    if (originalID != collatorLocaleName) {
         str::stream ss;
         ss << "Field '" << CollationSpec::kLocaleField << "' is invalid in: " << spec;
 
-        if (!str::equals(kFallbackLocaleName, collatorLocaleName) &&
-            !str::equals("", collatorLocaleName)) {
+        if ((collatorLocaleName != kFallbackLocaleName) && !collatorLocaleName.empty()) {
             ss << ". Did you mean '" << collatorLocaleName << "'?";
         }
 
diff --git a/src/mongo/db/query/index_bounds_builder.cpp b/src/mongo/db/query/index_bounds_builder.cpp
index c86a43a5f10..43c5a55772c 100644
--- a/src/mongo/db/query/index_bounds_builder.cpp
+++ b/src/mongo/db/query/index_bounds_builder.cpp
@@ -361,7 +361,7 @@ void IndexBoundsBuilder::_translatePredicate(const MatchExpression* expr,
     oilOut->name = elt.fieldName();
 
     bool isHashed = false;
-    if (mongoutils::str::equals("hashed", elt.valuestrsafe())) {
+    if (elt.valueStringDataSafe() == "hashed") {
         isHashed = true;
     }
 
@@ -716,15 +716,14 @@ void IndexBoundsBuilder::_translatePredicate(const MatchExpression* expr,
             unionize(oilOut);
     } else if (MatchExpression::GEO == expr->matchType()) {
         const GeoMatchExpression* gme = static_cast<const GeoMatchExpression*>(expr);
-
-        if (mongoutils::str::equals("2dsphere", elt.valuestrsafe())) {
+        if ("2dsphere" == elt.valueStringDataSafe()) {
             verify(gme->getGeoExpression().getGeometry().hasS2Region());
             const S2Region& region = gme->getGeoExpression().getGeometry().getS2Region();
             S2IndexingParams indexParams;
             ExpressionParams::initialize2dsphereParams(index.infoObj, index.collator, &indexParams);
             ExpressionMapping::cover2dsphere(region, indexParams, oilOut);
             *tightnessOut = IndexBoundsBuilder::INEXACT_FETCH;
-        } else if (mongoutils::str::equals("2d", elt.valuestrsafe())) {
+        } else if ("2d" == elt.valueStringDataSafe()) {
             verify(gme->getGeoExpression().getGeometry().hasR2Region());
             const R2Region& region = gme->getGeoExpression().getGeometry().getR2Region();
 
diff --git a/src/mongo/db/query/killcursors_request.cpp b/src/mongo/db/query/killcursors_request.cpp
index 34ebc74c59c..df44d73043d 100644
--- a/src/mongo/db/query/killcursors_request.cpp
+++ b/src/mongo/db/query/killcursors_request.cpp
@@ -37,7 +37,7 @@ namespace mongo {
 
 namespace {
 
-const char kCmdName[] = "killCursors";
+constexpr StringData kCmdName = "killCursors"_sd;
 const char kCursorsField[] = "cursors";
 
 }  // namespace
@@ -48,7 +48,7 @@ KillCursorsRequest::KillCursorsRequest(const NamespaceString& nsString,
 
 StatusWith<KillCursorsRequest> KillCursorsRequest::parseFromBSON(const std::string& dbname,
                                                                  const BSONObj& cmdObj) {
-    if (!str::equals(cmdObj.firstElement().fieldName(), kCmdName)) {
+    if (cmdObj.firstElement().fieldNameStringData() != kCmdName) {
         return {ErrorCodes::FailedToParse,
                 str::stream() << "First field name must be '" << kCmdName << "' in: " << cmdObj};
     }
diff --git a/src/mongo/db/query/parsed_projection.cpp b/src/mongo/db/query/parsed_projection.cpp
index bdd1909d97c..91b0156f8f4 100644
--- a/src/mongo/db/query/parsed_projection.cpp
+++ b/src/mongo/db/query/parsed_projection.cpp
@@ -78,7 +78,7 @@ Status ParsedProjection::make(OperationContext* opCtx,
             }
 
             BSONElement e2 = obj.firstElement();
-            if (mongoutils::str::equals(e2.fieldName(), "$slice")) {
+            if (e2.fieldNameStringData() == "$slice") {
                 if (e2.isNumber()) {
                     // This is A-OK.
                 } else if (e2.type() == Array) {
@@ -102,7 +102,7 @@ Status ParsedProjection::make(OperationContext* opCtx,
                 // Projections with $slice aren't covered.
                 requiresDocument = true;
                 pp->_arrayFields.push_back(elem.fieldNameStringData());
-            } else if (mongoutils::str::equals(e2.fieldName(), "$elemMatch")) {
+            } else if (e2.fieldNameStringData() == "$elemMatch") {
                 // Validate $elemMatch arguments and dependencies.
                 if (Object != e2.type()) {
                     return Status(ErrorCodes::BadValue,
@@ -147,7 +147,7 @@ Status ParsedProjection::make(OperationContext* opCtx,
                 // Projections with $elemMatch aren't covered.
                 requiresDocument = true;
                 pp->_arrayFields.push_back(elem.fieldNameStringData());
-            } else if (mongoutils::str::equals(e2.fieldName(), "$meta")) {
+            } else if (e2.fieldNameStringData() == "$meta") {
                 // Field for meta must be top level.  We can relax this at some point.
                 if (mongoutils::str::contains(elem.fieldName(), '.')) {
                     return Status(ErrorCodes::BadValue, "field for $meta cannot be nested");
@@ -190,7 +190,7 @@ Status ParsedProjection::make(OperationContext* opCtx,
                 return Status(ErrorCodes::BadValue,
                               string("Unsupported projection option: ") + elem.toString());
             }
-        } else if (mongoutils::str::equals(elem.fieldName(), "_id") && !elem.trueValue()) {
+        } else if ((elem.fieldNameStringData() == "_id") && !elem.trueValue()) {
             pp->_hasId = false;
         } else {
             pp->_hasDottedFieldPath = pp->_hasDottedFieldPath ||
@@ -291,7 +291,7 @@ Status ParsedProjection::make(OperationContext* opCtx,
         while (srcIt.more()) {
             BSONElement elt = srcIt.next();
             // We've already handled the _id field before entering this loop.
-            if (pp->_hasId && mongoutils::str::equals(elt.fieldName(), "_id")) {
+            if (pp->_hasId && (elt.fieldNameStringData() == "_id")) {
                 continue;
             }
             // $meta sortKey should not be checked as a part of _requiredFields, since it can
diff --git a/src/mongo/db/query/query_planner.cpp b/src/mongo/db/query/query_planner.cpp
index 0a45ee45dca..d7503c724a8 100644
--- a/src/mongo/db/query/query_planner.cpp
+++ b/src/mongo/db/query/query_planner.cpp
@@ -79,7 +79,7 @@ static bool is2DIndex(const BSONObj& pattern) {
     BSONObjIterator it(pattern);
     while (it.more()) {
         BSONElement e = it.next();
-        if (String == e.type() && str::equals("2d", e.valuestr())) {
+        if (String == e.type() && (e.valueStringData() == "2d")) {
             return true;
         }
     }
@@ -175,7 +175,7 @@ static bool indexCompatibleMaxMin(const BSONObj& obj,
         // Field names must match and be in the same order.
         BSONElement kpElt = kpIt.next();
         BSONElement objElt = objIt.next();
-        if (!mongoutils::str::equals(kpElt.fieldName(), objElt.fieldName())) {
+        if (kpElt.fieldNameStringData() != objElt.fieldNameStringData()) {
             return false;
         }
 
diff --git a/src/mongo/db/query/query_request.cpp b/src/mongo/db/query/query_request.cpp
index 7a990dd5b9f..6cdca0a5327 100644
--- a/src/mongo/db/query/query_request.cpp
+++ b/src/mongo/db/query/query_request.cpp
@@ -707,7 +707,7 @@ bool QueryRequest::isTextScoreMeta(BSONElement elt) {
         return false;
     }
     BSONElement metaElt = metaIt.next();
-    if (!str::equals("$meta", metaElt.fieldName())) {
+    if (metaElt.fieldNameStringData() != "$meta") {
         return false;
     }
     if (mongo::String != metaElt.type()) {
@@ -838,9 +838,9 @@ Status QueryRequest::initFullQuery(const BSONObj& top) {
 
     while (i.more()) {
         BSONElement e = i.next();
-        const char* name = e.fieldName();
+        StringData name = e.fieldNameStringData();
 
-        if (0 == strcmp("$orderby", name) || 0 == strcmp("orderby", name)) {
+        if (name == "$orderby" || name == "orderby") {
             if (Object == e.type()) {
                 _sort = e.embeddedObject().getOwned();
             } else if (Array == e.type()) {
@@ -878,22 +878,22 @@ Status QueryRequest::initFullQuery(const BSONObj& top) {
             } else {
                 return Status(ErrorCodes::BadValue, "sort must be object or array");
             }
-        } else if ('$' == *name) {
-            name++;
-            if (str::equals("explain", name)) {
+        } else if (name.startsWith("$")) {
+            name = name.substr(1);  // chop first char
+            if (name == "explain") {
                 // Won't throw.
                 _explain = e.trueValue();
-            } else if (str::equals("min", name)) {
+            } else if (name == "min") {
                 if (!e.isABSONObj()) {
                     return Status(ErrorCodes::BadValue, "$min must be a BSONObj");
                 }
                 _min = e.embeddedObject().getOwned();
-            } else if (str::equals("max", name)) {
+            } else if (name == "max") {
                 if (!e.isABSONObj()) {
                     return Status(ErrorCodes::BadValue, "$max must be a BSONObj");
                 }
                 _max = e.embeddedObject().getOwned();
-            } else if (str::equals("hint", name)) {
+            } else if (name == "hint") {
                 if (e.isABSONObj()) {
                     _hint = e.embeddedObject().getOwned();
                 } else if (String == e.type()) {
@@ -902,25 +902,25 @@ Status QueryRequest::initFullQuery(const BSONObj& top) {
                     return Status(ErrorCodes::BadValue,
                                   "$hint must be either a string or nested object");
                 }
-            } else if (str::equals("returnKey", name)) {
+            } else if (name == "returnKey") {
                 // Won't throw.
                 if (e.trueValue()) {
                     _returnKey = true;
                     addReturnKeyMetaProj();
                 }
-            } else if (str::equals("showDiskLoc", name)) {
+            } else if (name == "showDiskLoc") {
                 // Won't throw.
                 if (e.trueValue()) {
                     _showRecordId = true;
                     addShowRecordIdMetaProj();
                 }
-            } else if (str::equals("maxTimeMS", name)) {
+            } else if (name == "maxTimeMS") {
                 StatusWith<int> maxTimeMS = parseMaxTimeMS(e);
                 if (!maxTimeMS.isOK()) {
                     return maxTimeMS.getStatus();
                 }
                 _maxTimeMS = maxTimeMS.getValue();
-            } else if (str::equals("comment", name)) {
+            } else if (name == "comment") {
                 // Legacy $comment can be any BSON element. Convert to string if it isn't
                 // already.
                 if (e.type() == BSONType::String) {
diff --git a/src/mongo/db/repl/collection_cloner_test.cpp b/src/mongo/db/repl/collection_cloner_test.cpp
index c8f06889825..4cb8147c75d 100644
--- a/src/mongo/db/repl/collection_cloner_test.cpp
+++ b/src/mongo/db/repl/collection_cloner_test.cpp
@@ -525,7 +525,7 @@ TEST_F(CollectionClonerTest,
        CollectionClonerReturnsScheduleErrorOnFailingToScheduleListIndexesCommand) {
     TaskExecutorWithFailureInScheduleRemoteCommand _executorProxy(
         &getExecutor(), [](const executor::RemoteCommandRequest& request) {
-            return str::equals("listIndexes", request.cmdObj.firstElementFieldName());
+            return request.cmdObj.firstElementFieldNameStringData() == "listIndexes";
         });
 
     collectionCloner = stdx::make_unique<CollectionCloner>(&_executorProxy,
diff --git a/src/mongo/db/repl/database_cloner_test.cpp b/src/mongo/db/repl/database_cloner_test.cpp
index 07f7bc7bfff..e9f3a6fee90 100644
--- a/src/mongo/db/repl/database_cloner_test.cpp
+++ b/src/mongo/db/repl/database_cloner_test.cpp
@@ -250,7 +250,7 @@ TEST_F(DatabaseClonerTest,
        DatabaseClonerReturnsScheduleErrorOnFailingToScheduleListCollectionsCommand) {
     TaskExecutorWithFailureInScheduleRemoteCommand executorProxy(
         &getExecutor(), [](const executor::RemoteCommandRequest& request) {
-            return str::equals("listCollections", request.cmdObj.firstElementFieldName());
+            return request.cmdObj.firstElementFieldNameStringData() == "listCollections";
         });
 
     DatabaseCloner databaseCloner(&executorProxy,
diff --git a/src/mongo/db/repl/databases_cloner_test.cpp b/src/mongo/db/repl/databases_cloner_test.cpp
index c4828eca321..f381077c4ab 100644
--- a/src/mongo/db/repl/databases_cloner_test.cpp
+++ b/src/mongo/db/repl/databases_cloner_test.cpp
@@ -791,7 +791,7 @@ TEST_F(DBsClonerTest, FailingToScheduleSecondDatabaseClonerShouldCancelTheCloner
 
     TaskExecutorWithFailureInScheduleRemoteCommand _executorProxy(
         &getExecutor(), [](const executor::RemoteCommandRequest& request) {
-            return str::equals("listCollections", request.cmdObj.firstElementFieldName()) &&
+            return request.cmdObj.firstElementFieldNameStringData() == "listCollections" &&
                 request.dbname == "b";
         });
 
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index 613683144e4..f421603e99f 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -1470,7 +1470,7 @@ Status applyOperation_inlock(OperationContext* opCtx,
         uassert(ErrorCodes::InvalidNamespace,
                 "'ns' must be of type String",
                 fieldNs.type() == BSONType::String);
-        const StringData ns = fieldNs.valuestrsafe();
+        const StringData ns = fieldNs.valueStringDataSafe();
         requestNss = NamespaceString(ns);
         invariant(requestNss.coll().size());
         dassert(opCtx->lockState()->isCollectionLockedForMode(
@@ -1711,7 +1711,7 @@ Status applyOperation_inlock(OperationContext* opCtx,
                 request.setUpsert();
                 request.setFromOplogApplication(true);
 
-                const StringData ns = fieldNs.valuestrsafe();
+                const StringData ns = fieldNs.valueStringDataSafe();
                 writeConflictRetry(opCtx, "applyOps_upsert", ns, [&] {
                     WriteUnitOfWork wuow(opCtx);
                     // If this is an atomic applyOps (i.e: `haveWrappingWriteUnitOfWork` is true),
@@ -1762,7 +1762,7 @@ Status applyOperation_inlock(OperationContext* opCtx,
             timestamp = fieldTs.timestamp();
         }
 
-        const StringData ns = fieldNs.valuestrsafe();
+        const StringData ns = fieldNs.valueStringDataSafe();
         auto status = writeConflictRetry(opCtx, "applyOps_update", ns, [&] {
             WriteUnitOfWork wuow(opCtx);
             if (timestamp != Timestamp::min()) {
@@ -1841,7 +1841,7 @@ Status applyOperation_inlock(OperationContext* opCtx,
             timestamp = fieldTs.timestamp();
         }
 
-        const StringData ns = fieldNs.valuestrsafe();
+        const StringData ns = fieldNs.valueStringDataSafe();
         writeConflictRetry(opCtx, "applyOps_delete", ns, [&] {
             WriteUnitOfWork wuow(opCtx);
             if (timestamp != Timestamp::min()) {
diff --git a/src/mongo/db/s/check_sharding_index_command.cpp b/src/mongo/db/s/check_sharding_index_command.cpp
index da7f1700869..7bc56741ae8 100644
--- a/src/mongo/db/s/check_sharding_index_command.cpp
+++ b/src/mongo/db/s/check_sharding_index_command.cpp
@@ -97,7 +97,7 @@ public:
             return false;
         }
 
-        if (keyPattern.nFields() == 1 && str::equals("_id", keyPattern.firstElementFieldName())) {
+        if (keyPattern.nFields() == 1 && keyPattern.firstElementFieldNameStringData() == "_id") {
             result.appendBool("idskip", true);
             return true;
         }
diff --git a/src/mongo/db/s/config/configsvr_shard_collection_command.cpp b/src/mongo/db/s/config/configsvr_shard_collection_command.cpp
index cbbcee65059..30824550e1e 100644
--- a/src/mongo/db/s/config/configsvr_shard_collection_command.cpp
+++ b/src/mongo/db/s/config/configsvr_shard_collection_command.cpp
@@ -353,7 +353,7 @@ void validateShardKeyAgainstExistingIndexes(OperationContext* opCtx,
         } else {
             bool isExplicitlyUnique = eqQueryResult["unique"].trueValue();
             BSONObj currKey = eqQueryResult["key"].embeddedObject();
-            bool isCurrentID = str::equals(currKey.firstElementFieldName(), "_id");
+            bool isCurrentID = (currKey.firstElementFieldNameStringData() == "_id");
             uassert(ErrorCodes::InvalidOptions,
                     str::stream() << "can't shard collection " << nss.ns() << ", " << proposedKey
                                   << " index not unique, and unique index explicitly specified",
diff --git a/src/mongo/db/s/shardsvr_shard_collection.cpp b/src/mongo/db/s/shardsvr_shard_collection.cpp
index e6bff1ed444..bfb106786f3 100644
--- a/src/mongo/db/s/shardsvr_shard_collection.cpp
+++ b/src/mongo/db/s/shardsvr_shard_collection.cpp
@@ -248,7 +248,7 @@ void createCollectionOrValidateExisting(OperationContext* opCtx,
         } else {
             bool isExplicitlyUnique = eqQueryResult["unique"].trueValue();
             BSONObj currKey = eqQueryResult["key"].embeddedObject();
-            bool isCurrentID = str::equals(currKey.firstElementFieldName(), "_id");
+            bool isCurrentID = (currKey.firstElementFieldNameStringData() == "_id");
             uassert(ErrorCodes::InvalidOptions,
                     str::stream() << "can't shard collection " << nss.ns() << ", " << proposedKey
                                   << " index not unique, and unique index explicitly specified",
@@ -308,13 +308,14 @@ void validateShardKeyAgainstExistingZones(OperationContext* opCtx,
                                   << " -->> "
                                   << tag.getMaxKey()
                                   << " have non-matching keys",
-                    str::equals(tagMinKeyElement.fieldName(), tagMaxKeyElement.fieldName()));
+                    tagMinKeyElement.fieldNameStringData() ==
+                        tagMaxKeyElement.fieldNameStringData());
 
             BSONElement proposedKeyElement = proposedFields.next();
-            bool match =
-                (str::equals(tagMinKeyElement.fieldName(), proposedKeyElement.fieldName()) &&
-                 ((tagMinFields.more() && proposedFields.more()) ||
-                  (!tagMinFields.more() && !proposedFields.more())));
+            bool match = ((tagMinKeyElement.fieldNameStringData() ==
+                           proposedKeyElement.fieldNameStringData()) &&
+                          ((tagMinFields.more() && proposedFields.more()) ||
+                           (!tagMinFields.more() && !proposedFields.more())));
             uassert(ErrorCodes::InvalidOptions,
                     str::stream() << "the proposed shard key " << proposedKey.toString()
                                   << " does not match with the shard key of the existing zone "