diff --git a/libutils/Android.bp b/libutils/Android.bp
index 8be4dd0..30798dd 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -205,6 +205,7 @@
         "Mutex_test.cpp",
         "SharedBuffer_test.cpp",
         "String8_test.cpp",
+        "String16_test.cpp",
         "StrongPointer_test.cpp",
         "Unicode_test.cpp",
         "Vector_test.cpp",
diff --git a/libutils/SharedBuffer.cpp b/libutils/SharedBuffer.cpp
index 7910c6e..3e703db 100644
--- a/libutils/SharedBuffer.cpp
+++ b/libutils/SharedBuffer.cpp
@@ -41,6 +41,7 @@
         // The following is OK on Android-supported platforms.
         sb->mRefs.store(1, std::memory_order_relaxed);
         sb->mSize = size;
+        sb->mClientMetadata = 0;
     }
     return sb;
 }
diff --git a/libutils/SharedBuffer.h b/libutils/SharedBuffer.h
index fdf13a9..476c842 100644
--- a/libutils/SharedBuffer.h
+++ b/libutils/SharedBuffer.h
@@ -102,7 +102,12 @@
         // Must be sized to preserve correct alignment.
         mutable std::atomic<int32_t>        mRefs;
                 size_t                      mSize;
-                uint32_t                    mReserved[2];
+                uint32_t                    mReserved;
+public:
+        // mClientMetadata is reserved for client use.  It is initialized to 0
+        // and the clients can do whatever they want with it.  Note that this is
+        // placed last so that it is adjcent to the buffer allocated.
+                uint32_t                    mClientMetadata;
 };
 
 static_assert(sizeof(SharedBuffer) % 8 == 0
diff --git a/libutils/String16.cpp b/libutils/String16.cpp
index 818b171..5c3cf32 100644
--- a/libutils/String16.cpp
+++ b/libutils/String16.cpp
@@ -24,21 +24,21 @@
 
 namespace android {
 
+static const StaticString16 emptyString(u"");
 static inline char16_t* getEmptyString() {
-    static SharedBuffer* gEmptyStringBuf = [] {
-        SharedBuffer* buf = SharedBuffer::alloc(sizeof(char16_t));
-        char16_t* str = static_cast<char16_t*>(buf->data());
-        *str = 0;
-        return buf;
-    }();
-
-    gEmptyStringBuf->acquire();
-    return static_cast<char16_t*>(gEmptyStringBuf->data());
+    return const_cast<char16_t*>(emptyString.string());
 }
 
 // ---------------------------------------------------------------------------
 
-static char16_t* allocFromUTF8(const char* u8str, size_t u8len)
+void* String16::alloc(size_t size)
+{
+    SharedBuffer* buf = SharedBuffer::alloc(size);
+    buf->mClientMetadata = kIsSharedBufferAllocated;
+    return buf;
+}
+
+char16_t* String16::allocFromUTF8(const char* u8str, size_t u8len)
 {
     if (u8len == 0) return getEmptyString();
 
@@ -49,7 +49,7 @@
         return getEmptyString();
     }
 
-    SharedBuffer* buf = SharedBuffer::alloc(sizeof(char16_t)*(u16len+1));
+    SharedBuffer* buf = static_cast<SharedBuffer*>(alloc(sizeof(char16_t) * (u16len + 1)));
     if (buf) {
         u8cur = (const uint8_t*) u8str;
         char16_t* u16str = (char16_t*)buf->data();
@@ -66,13 +66,13 @@
     return getEmptyString();
 }
 
-static char16_t* allocFromUTF16(const char16_t* u16str, size_t u16len) {
+char16_t* String16::allocFromUTF16(const char16_t* u16str, size_t u16len) {
     if (u16len >= SIZE_MAX / sizeof(char16_t)) {
         android_errorWriteLog(0x534e4554, "73826242");
         abort();
     }
 
-    SharedBuffer* buf = SharedBuffer::alloc((u16len + 1) * sizeof(char16_t));
+    SharedBuffer* buf = static_cast<SharedBuffer*>(alloc((u16len + 1) * sizeof(char16_t)));
     ALOG_ASSERT(buf, "Unable to allocate shared buffer");
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
@@ -97,8 +97,8 @@
     // having run. In this case we always allocate an empty string. It's less
     // efficient than using getEmptyString(), but we assume it's uncommon.
 
-    char16_t* data = static_cast<char16_t*>(
-            SharedBuffer::alloc(sizeof(char16_t))->data());
+    SharedBuffer* buf = static_cast<SharedBuffer*>(alloc(sizeof(char16_t)));
+    char16_t* data = static_cast<char16_t*>(buf->data());
     data[0] = 0;
     mString = data;
 }
@@ -106,7 +106,7 @@
 String16::String16(const String16& o)
     : mString(o.mString)
 {
-    SharedBuffer::bufferFromData(mString)->acquire();
+    acquire();
 }
 
 String16::String16(const String16& o, size_t len, size_t begin)
@@ -136,26 +136,30 @@
 
 String16::~String16()
 {
-    SharedBuffer::bufferFromData(mString)->release();
+    release();
 }
 
 size_t String16::size() const
 {
-    return SharedBuffer::sizeFromData(mString)/sizeof(char16_t)-1;
+    if (isStaticString()) {
+        return staticStringSize();
+    } else {
+        return SharedBuffer::sizeFromData(mString) / sizeof(char16_t) - 1;
+    }
 }
 
 void String16::setTo(const String16& other)
 {
-    SharedBuffer::bufferFromData(other.mString)->acquire();
-    SharedBuffer::bufferFromData(mString)->release();
+    release();
     mString = other.mString;
+    acquire();
 }
 
 status_t String16::setTo(const String16& other, size_t len, size_t begin)
 {
     const size_t N = other.size();
     if (begin >= N) {
-        SharedBuffer::bufferFromData(mString)->release();
+        release();
         mString = getEmptyString();
         return OK;
     }
@@ -184,8 +188,7 @@
         abort();
     }
 
-    SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-        ->editResize((len+1)*sizeof(char16_t));
+    SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memmove(str, other, len*sizeof(char16_t));
@@ -212,8 +215,8 @@
         abort();
     }
 
-    SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-        ->editResize((myLen+otherLen+1)*sizeof(char16_t));
+    SharedBuffer* buf =
+            static_cast<SharedBuffer*>(editResize((myLen + otherLen + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memcpy(str+myLen, other, (otherLen+1)*sizeof(char16_t));
@@ -238,8 +241,8 @@
         abort();
     }
 
-    SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-        ->editResize((myLen+otherLen+1)*sizeof(char16_t));
+    SharedBuffer* buf =
+            static_cast<SharedBuffer*>(editResize((myLen + otherLen + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memcpy(str+myLen, chrs, otherLen*sizeof(char16_t));
@@ -273,8 +276,8 @@
            len, myLen, String8(chrs, len).string());
     #endif
 
-    SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-        ->editResize((myLen+len+1)*sizeof(char16_t));
+    SharedBuffer* buf =
+            static_cast<SharedBuffer*>(editResize((myLen + len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         if (pos < myLen) {
@@ -338,23 +341,87 @@
     return strstr16(mString, chrs) != nullptr;
 }
 
+void* String16::edit() {
+    SharedBuffer* buf;
+    if (isStaticString()) {
+        buf = static_cast<SharedBuffer*>(alloc((size() + 1) * sizeof(char16_t)));
+        if (buf) {
+            buf->acquire();
+            memcpy(buf->data(), mString, (size() + 1) * sizeof(char16_t));
+        }
+    } else {
+        buf = SharedBuffer::bufferFromData(mString)->edit();
+        buf->mClientMetadata = kIsSharedBufferAllocated;
+    }
+    return buf;
+}
+
+void* String16::editResize(size_t newSize) {
+    SharedBuffer* buf;
+    if (isStaticString()) {
+        size_t copySize = (size() + 1) * sizeof(char16_t);
+        if (newSize < copySize) {
+            copySize = newSize;
+        }
+        buf = static_cast<SharedBuffer*>(alloc(newSize));
+        if (buf) {
+            buf->acquire();
+            memcpy(buf->data(), mString, copySize);
+        }
+    } else {
+        buf = SharedBuffer::bufferFromData(mString)->editResize(newSize);
+        buf->mClientMetadata = kIsSharedBufferAllocated;
+    }
+    return buf;
+}
+
+void String16::acquire()
+{
+    if (!isStaticString()) {
+        SharedBuffer::bufferFromData(mString)->acquire();
+    }
+}
+
+void String16::release()
+{
+    if (!isStaticString()) {
+        SharedBuffer::bufferFromData(mString)->release();
+    }
+}
+
+bool String16::isStaticString() const {
+    // See String16.h for notes on the memory layout of String16::StaticData and
+    // SharedBuffer.
+    static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
+    const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
+    return (*(p - 1) & kIsSharedBufferAllocated) == 0;
+}
+
+size_t String16::staticStringSize() const {
+    // See String16.h for notes on the memory layout of String16::StaticData and
+    // SharedBuffer.
+    static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
+    const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
+    return static_cast<size_t>(*(p - 1));
+}
+
 status_t String16::makeLower()
 {
     const size_t N = size();
     const char16_t* str = string();
-    char16_t* edit = nullptr;
+    char16_t* edited = nullptr;
     for (size_t i=0; i<N; i++) {
         const char16_t v = str[i];
         if (v >= 'A' && v <= 'Z') {
-            if (!edit) {
-                SharedBuffer* buf = SharedBuffer::bufferFromData(mString)->edit();
+            if (!edited) {
+                SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
                 if (!buf) {
                     return NO_MEMORY;
                 }
-                edit = (char16_t*)buf->data();
-                mString = str = edit;
+                edited = (char16_t*)buf->data();
+                mString = str = edited;
             }
-            edit[i] = tolower((char)v);
+            edited[i] = tolower((char)v);
         }
     }
     return OK;
@@ -364,18 +431,18 @@
 {
     const size_t N = size();
     const char16_t* str = string();
-    char16_t* edit = nullptr;
+    char16_t* edited = nullptr;
     for (size_t i=0; i<N; i++) {
         if (str[i] == replaceThis) {
-            if (!edit) {
-                SharedBuffer* buf = SharedBuffer::bufferFromData(mString)->edit();
+            if (!edited) {
+                SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
                 if (!buf) {
                     return NO_MEMORY;
                 }
-                edit = (char16_t*)buf->data();
-                mString = str = edit;
+                edited = (char16_t*)buf->data();
+                mString = str = edited;
             }
-            edit[i] = withThis;
+            edited[i] = withThis;
         }
     }
     return OK;
@@ -385,7 +452,7 @@
 {
     const size_t N = size();
     if (begin >= N) {
-        SharedBuffer::bufferFromData(mString)->release();
+        release();
         mString = getEmptyString();
         return OK;
     }
@@ -395,8 +462,7 @@
     }
 
     if (begin > 0) {
-        SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-            ->editResize((N+1)*sizeof(char16_t));
+        SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((N + 1) * sizeof(char16_t)));
         if (!buf) {
             return NO_MEMORY;
         }
@@ -404,8 +470,7 @@
         memmove(str, str+begin, (N-begin+1)*sizeof(char16_t));
         mString = str;
     }
-    SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
-        ->editResize((len+1)*sizeof(char16_t));
+    SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         str[len] = 0;
diff --git a/libutils/String16_test.cpp b/libutils/String16_test.cpp
new file mode 100644
index 0000000..f1f24c3
--- /dev/null
+++ b/libutils/String16_test.cpp
@@ -0,0 +1,218 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <utils/String16.h>
+#include <utils/String8.h>
+
+#include <gtest/gtest.h>
+
+namespace android {
+
+::testing::AssertionResult Char16_tStringEquals(const char16_t* a, const char16_t* b) {
+    if (strcmp16(a, b) != 0) {
+        return ::testing::AssertionFailure()
+               << "\"" << String8(a).c_str() << "\" not equal to \"" << String8(b).c_str() << "\"";
+    }
+    return ::testing::AssertionSuccess();
+}
+
+#define EXPECT_STR16EQ(a, b) EXPECT_TRUE(Char16_tStringEquals(a, b))
+
+TEST(String16Test, FromChar16_t) {
+    String16 tmp(u"Verify me");
+    EXPECT_STR16EQ(u"Verify me", tmp);
+}
+
+TEST(String16Test, FromChar16_tSized) {
+    String16 tmp(u"Verify me", 7);
+    EXPECT_STR16EQ(u"Verify ", tmp);
+}
+
+TEST(String16Test, FromChar) {
+    String16 tmp("Verify me");
+    EXPECT_STR16EQ(u"Verify me", tmp);
+}
+
+TEST(String16Test, FromCharSized) {
+    String16 tmp("Verify me", 7);
+    EXPECT_STR16EQ(u"Verify ", tmp);
+}
+
+TEST(String16Test, Copy) {
+    String16 tmp("Verify me");
+    String16 another = tmp;
+    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", another);
+}
+
+TEST(String16Test, Move) {
+    String16 tmp("Verify me");
+    String16 another(std::move(tmp));
+    EXPECT_STR16EQ(u"Verify me", another);
+}
+
+TEST(String16Test, Size) {
+    String16 tmp("Verify me");
+    EXPECT_EQ(9U, tmp.size());
+}
+
+TEST(String16Test, setTo) {
+    String16 tmp("Verify me");
+    tmp.setTo(u"New content");
+    EXPECT_EQ(11U, tmp.size());
+    EXPECT_STR16EQ(u"New content", tmp);
+}
+
+TEST(String16Test, Append) {
+    String16 tmp("Verify me");
+    tmp.append(String16("Hello"));
+    EXPECT_EQ(14U, tmp.size());
+    EXPECT_STR16EQ(u"Verify meHello", tmp);
+}
+
+TEST(String16Test, Insert) {
+    String16 tmp("Verify me");
+    tmp.insert(6, u"Insert");
+    EXPECT_EQ(15U, tmp.size());
+    EXPECT_STR16EQ(u"VerifyInsert me", tmp);
+}
+
+TEST(String16Test, Remove) {
+    String16 tmp("Verify me");
+    tmp.remove(2, 6);
+    EXPECT_EQ(2U, tmp.size());
+    EXPECT_STR16EQ(u" m", tmp);
+}
+
+TEST(String16Test, MakeLower) {
+    String16 tmp("Verify Me!");
+    tmp.makeLower();
+    EXPECT_EQ(10U, tmp.size());
+    EXPECT_STR16EQ(u"verify me!", tmp);
+}
+
+TEST(String16Test, ReplaceAll) {
+    String16 tmp("Verify verify Verify");
+    tmp.replaceAll(u'r', u'!');
+    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp);
+}
+
+TEST(String16Test, Compare) {
+    String16 tmp("Verify me");
+    EXPECT_EQ(String16(u"Verify me"), tmp);
+}
+
+TEST(String16Test, StaticString) {
+    String16 nonStaticString("NonStatic");
+    StaticString16 staticString(u"Static");
+
+    EXPECT_TRUE(staticString.isStaticString());
+    EXPECT_FALSE(nonStaticString.isStaticString());
+}
+
+TEST(String16Test, StaticStringCopy) {
+    StaticString16 tmp(u"Verify me");
+    String16 another = tmp;
+    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_TRUE(tmp.isStaticString());
+    EXPECT_TRUE(another.isStaticString());
+}
+
+TEST(String16Test, StaticStringMove) {
+    StaticString16 tmp(u"Verify me");
+    String16 another(std::move(tmp));
+    EXPECT_STR16EQ(u"Verify me", another);
+    EXPECT_TRUE(another.isStaticString());
+}
+
+TEST(String16Test, StaticStringSize) {
+    StaticString16 tmp(u"Verify me");
+    EXPECT_EQ(9U, tmp.size());
+}
+
+TEST(String16Test, StaticStringSetTo) {
+    StaticString16 tmp(u"Verify me");
+    tmp.setTo(u"New content");
+    EXPECT_EQ(11U, tmp.size());
+    EXPECT_STR16EQ(u"New content", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringAppend) {
+    StaticString16 tmp(u"Verify me");
+    tmp.append(String16("Hello"));
+    EXPECT_EQ(14U, tmp.size());
+    EXPECT_STR16EQ(u"Verify meHello", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringInsert) {
+    StaticString16 tmp(u"Verify me");
+    tmp.insert(6, u"Insert");
+    EXPECT_EQ(15U, tmp.size());
+    EXPECT_STR16EQ(u"VerifyInsert me", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringRemove) {
+    StaticString16 tmp(u"Verify me");
+    tmp.remove(2, 6);
+    EXPECT_EQ(2U, tmp.size());
+    EXPECT_STR16EQ(u" m", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringMakeLower) {
+    StaticString16 tmp(u"Verify me!");
+    tmp.makeLower();
+    EXPECT_EQ(10U, tmp.size());
+    EXPECT_STR16EQ(u"verify me!", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringReplaceAll) {
+    StaticString16 tmp(u"Verify verify Verify");
+    tmp.replaceAll(u'r', u'!');
+    EXPECT_STR16EQ(u"Ve!ify ve!ify Ve!ify", tmp);
+    EXPECT_FALSE(tmp.isStaticString());
+}
+
+TEST(String16Test, StaticStringCompare) {
+    StaticString16 tmp(u"Verify me");
+    EXPECT_EQ(String16(u"Verify me"), tmp);
+}
+
+TEST(String16Test, StringSetToStaticString) {
+    StaticString16 tmp(u"Verify me");
+    String16 another(u"nonstatic");
+    another = tmp;
+    EXPECT_STR16EQ(u"Verify me", tmp);
+    EXPECT_STR16EQ(u"Verify me", another);
+}
+
+TEST(String16Test, StringMoveFromStaticString) {
+    StaticString16 tmp(u"Verify me");
+    String16 another(std::move(tmp));
+    EXPECT_STR16EQ(u"Verify me", another);
+}
+
+TEST(String16Test, EmptyStringIsStatic) {
+    String16 tmp("");
+    EXPECT_TRUE(tmp.isStaticString());
+}
+
+}  // namespace android
diff --git a/libutils/include/utils/String16.h b/libutils/include/utils/String16.h
index afbc2ed..adc3e7d 100644
--- a/libutils/include/utils/String16.h
+++ b/libutils/include/utils/String16.h
@@ -37,13 +37,17 @@
 
 class String8;
 
+template <size_t N>
+class StaticString16;
+
 // DO NOT USE: please use std::u16string
 
 //! This is a string holding UTF-16 characters.
 class String16
 {
 public:
-    /* use String16(StaticLinkage) if you're statically linking against
+    /*
+     * Use String16(StaticLinkage) if you're statically linking against
      * libutils and declaring an empty static String16, e.g.:
      *
      *   static String16 sAStaticEmptyString(String16::kEmptyString);
@@ -123,8 +127,76 @@
 
     inline                      operator const char16_t*() const;
 
-private:
-            const char16_t*     mString;
+    // Static and non-static String16 behave the same for the users, so
+    // this method isn't of much use for the users. It is public for testing.
+            bool                isStaticString() const;
+
+  private:
+    /*
+     * A flag indicating the type of underlying buffer.
+     */
+    static constexpr uint32_t kIsSharedBufferAllocated = 0x80000000;
+
+    /*
+     * alloc() returns void* so that SharedBuffer class is not exposed.
+     */
+    static void* alloc(size_t size);
+    static char16_t* allocFromUTF8(const char* u8str, size_t u8len);
+    static char16_t* allocFromUTF16(const char16_t* u16str, size_t u16len);
+
+    /*
+     * edit() and editResize() return void* so that SharedBuffer class
+     * is not exposed.
+     */
+    void* edit();
+    void* editResize(size_t new_size);
+
+    void acquire();
+    void release();
+
+    size_t staticStringSize() const;
+
+    const char16_t* mString;
+
+protected:
+    /*
+     * Data structure used to allocate static storage for static String16.
+     *
+     * Note that this data structure and SharedBuffer are used interchangably
+     * as the underlying data structure for a String16.  Therefore, the layout
+     * of this data structure must match the part in SharedBuffer that is
+     * visible to String16.
+     */
+    template <size_t N>
+    struct StaticData {
+        // The high bit of 'size' is used as a flag.
+        static_assert(N - 1 < kIsSharedBufferAllocated, "StaticString16 too long!");
+        constexpr StaticData() : size(N - 1), data{0} {}
+        const uint32_t size;
+        char16_t data[N];
+
+        constexpr StaticData(const StaticData<N>&) = default;
+    };
+
+    /*
+     * Helper function for constructing a StaticData object.
+     */
+    template <size_t N>
+    static constexpr const StaticData<N> makeStaticData(const char16_t (&s)[N]) {
+        StaticData<N> r;
+        // The 'size' field is at the same location where mClientMetadata would
+        // be for a SharedBuffer.  We do NOT set kIsSharedBufferAllocated flag
+        // here.
+        for (size_t i = 0; i < N - 1; ++i) r.data[i] = s[i];
+        return r;
+    }
+
+    template <size_t N>
+    explicit constexpr String16(const StaticData<N>& s) : mString(s.data) {}
+
+public:
+    template <size_t N>
+    explicit constexpr String16(const StaticString16<N>& s) : mString(s.mString) {}
 };
 
 // String16 can be trivially moved using memcpy() because moving does not
@@ -132,6 +204,42 @@
 ANDROID_TRIVIAL_MOVE_TRAIT(String16)
 
 // ---------------------------------------------------------------------------
+
+/*
+ * A StaticString16 object is a specialized String16 object.  Instead of holding
+ * the string data in a ref counted SharedBuffer object, it holds data in a
+ * buffer within StaticString16 itself.  Note that this buffer is NOT ref
+ * counted and is assumed to be available for as long as there is at least a
+ * String16 object using it.  Therefore, one must be extra careful to NEVER
+ * assign a StaticString16 to a String16 that outlives the StaticString16
+ * object.
+ *
+ * THE SAFEST APPROACH IS TO USE StaticString16 ONLY AS GLOBAL VARIABLES.
+ *
+ * A StaticString16 SHOULD NEVER APPEAR IN APIs.  USE String16 INSTEAD.
+ */
+template <size_t N>
+class StaticString16 : public String16 {
+public:
+    constexpr StaticString16(const char16_t (&s)[N]) : String16(mData), mData(makeStaticData(s)) {}
+
+    constexpr StaticString16(const StaticString16<N>& other)
+        : String16(mData), mData(other.mData) {}
+
+    constexpr StaticString16(const StaticString16<N>&&) = delete;
+
+    // There is no reason why one would want to 'new' a StaticString16.  Delete
+    // it to discourage misuse.
+    static void* operator new(std::size_t) = delete;
+
+private:
+    const StaticData<N> mData;
+};
+
+template <typename F>
+StaticString16(const F&)->StaticString16<sizeof(F) / sizeof(char16_t)>;
+
+// ---------------------------------------------------------------------------
 // No user servicable parts below.
 
 inline int compare_type(const String16& lhs, const String16& rhs)