diff --git a/icu4c/source/common/charstr.h b/icu4c/source/common/charstr.h
index 7749a804b93..08283ca452c 100644
--- a/icu4c/source/common/charstr.h
+++ b/icu4c/source/common/charstr.h
@@ -104,6 +104,13 @@ public:
      */
     int32_t extract(char *dest, int32_t capacity, UErrorCode &errorCode) const;
 
+    bool operator==(const CharString& other) const {
+        return len == other.length() && (len == 0 || uprv_memcmp(data(), other.data(), len) == 0);
+    }
+    bool operator!=(const CharString& other) const {
+        return !operator==(other);
+    }
+
     bool operator==(StringPiece other) const {
         return len == other.length() && (len == 0 || uprv_memcmp(data(), other.data(), len) == 0);
     }
diff --git a/icu4c/source/common/uresbund.cpp b/icu4c/source/common/uresbund.cpp
index cbe5aabf127..6886e78e50b 100644
--- a/icu4c/source/common/uresbund.cpp
+++ b/icu4c/source/common/uresbund.cpp
@@ -244,7 +244,7 @@ static bool getParentLocaleID(char *name, const char *origName, UResOpenType ope
         // if "name" has both script and region, is the script the default script?
         // - if so, remove it and keep the region
         // - if not, remove the region and keep the script
-        if (getDefaultScript(language, region) == script.toStringPiece()) {
+        if (getDefaultScript(language, region) == script) {
             workingLocale.append(language, err).append("_", err).append(region, err);
         } else {
             workingLocale.append(language, err).append("_", err).append(script, err);
@@ -272,7 +272,7 @@ static bool getParentLocaleID(char *name, const char *origName, UResOpenType ope
         // - if not, return false to continue up the chain
         // (we don't do this for other open types for the same reason we don't look things up in the parent
         // locale table for other open types-- see the reference to UTS #35 above)
-        if (openType != URES_OPEN_LOCALE_DEFAULT_ROOT || getDefaultScript(language, CharString()) == script.toStringPiece()) {
+        if (openType != URES_OPEN_LOCALE_DEFAULT_ROOT || getDefaultScript(language, CharString()) == script) {
             workingLocale.append(language, err);
         } else {
             return false;
@@ -3168,7 +3168,7 @@ ures_getFunctionalEquivalent(char *result, int32_t resultCapacity,
             found.clear().append(ures_getLocaleByType(res, ULOC_VALID_LOCALE, &subStatus), subStatus);
         }
 
-        if (found != parent.toStringPiece()) {
+        if (found != parent) {
             parent.copyFrom(found, subStatus);
         } else {
             getParentForFunctionalEquivalent(found.data(),res,&bund1,parent);
@@ -3277,7 +3277,7 @@ ures_getFunctionalEquivalent(char *result, int32_t resultCapacity,
         subStatus = U_ZERO_ERROR;
     } while(full.isEmpty() && !found.isEmpty() && U_SUCCESS(*status));
 
-    if(full.isEmpty() && kwVal != defVal.toStringPiece()) {
+    if(full.isEmpty() && kwVal != defVal) {
 #if defined(URES_TREE_DEBUG)
         fprintf(stderr, "Failed to locate kw %s - try default %s\n", kwVal.data(), defVal.data());
 #endif
@@ -3361,7 +3361,7 @@ ures_getFunctionalEquivalent(char *result, int32_t resultCapacity,
 #endif        
           if(defLoc.length() <= full.length()) {
             /* found the keyword in a *child* of where the default tag was present. */
-            if(kwVal == defVal.toStringPiece()) { /* if the requested kw is default, */
+            if(kwVal == defVal) { /* if the requested kw is default, */
               /* and the default is in or in an ancestor of the current locale */
 #if defined(URES_TREE_DEBUG)
               fprintf(stderr, "Removing unneeded var %s=%s\n", keyword, kwVal.data());
diff --git a/icu4c/source/i18n/units_data.cpp b/icu4c/source/i18n/units_data.cpp
index b1e069660f2..40d148379d2 100644
--- a/icu4c/source/i18n/units_data.cpp
+++ b/icu4c/source/i18n/units_data.cpp
@@ -382,7 +382,7 @@ void U_I18N_API getAllConversionRates(MaybeStackVector<ConversionRateInfo> &resu
 const ConversionRateInfo *ConversionRates::extractConversionInfo(StringPiece source,
                                                                  UErrorCode &status) const {
     for (size_t i = 0, n = conversionInfo_.length(); i < n; ++i) {
-        if (conversionInfo_[i]->sourceUnit.toStringPiece() == source) return conversionInfo_[i];
+        if (conversionInfo_[i]->sourceUnit == source) return conversionInfo_[i];
     }
 
     status = U_INTERNAL_PROGRAM_ERROR;