AK: Move String::bytes() and String::operator==(String) to StringBase

The idea is to eventually get rid of protected state in StringBase. To
do this, we first need to remove all references to m_data and
m_short_string from String.

AK/String.cpp

@@ -213,13 +213,6 @@ StringView String::bytes_as_string_view() const
     return StringView(bytes());
 }
 
-ReadonlyBytes String::bytes() const
-{
-    if (is_short_string())
-        return m_short_string.bytes();
-    return m_data->bytes();
-}
-
 bool String::is_empty() const
 {
     return bytes().size() == 0;
@@ -291,13 +284,6 @@ Optional<size_t> String::find_byte_offset(StringView substring, size_t from_byte
     return {};
 }
 
-bool String::operator==(String const& other) const
-{
-    if (is_short_string())
-        return m_data == other.m_data;
-    return bytes_as_string_view() == other.bytes_as_string_view();
-}
-
 bool String::operator==(FlyString const& other) const
 {
     if (reinterpret_cast<uintptr_t>(m_data) == other.data({}))

AK/String.h

@@ -121,10 +121,6 @@ public:
     // Returns an iterable view over the Unicode code points.
     [[nodiscard]] Utf8View code_points() const;
 
-    // Returns the underlying UTF-8 encoded bytes.
-    // NOTE: There is no guarantee about null-termination.
-    [[nodiscard]] ReadonlyBytes bytes() const;
-
     // Returns true if the String is zero-length.
     [[nodiscard]] bool is_empty() const;
 
@@ -146,7 +142,7 @@ public:
     Optional<size_t> find_byte_offset(u32 code_point, size_t from_byte_offset = 0) const;
     Optional<size_t> find_byte_offset(StringView substring, size_t from_byte_offset = 0) const;
 
-    [[nodiscard]] bool operator==(String const&) const;
+    [[nodiscard]] bool operator==(String const&) const = default;
     [[nodiscard]] bool operator==(FlyString const&) const;
     [[nodiscard]] bool operator==(StringView) const;
     [[nodiscard]] bool operator==(char const* cstring) const;

AK/StringBase.cpp

@@ -59,4 +59,18 @@ bool StringBase::is_short_string() const
     return has_short_string_bit(reinterpret_cast<uintptr_t>(m_data));
 }
 
+ReadonlyBytes StringBase::bytes() const
+{
+    if (is_short_string())
+        return m_short_string.bytes();
+    return m_data->bytes();
+}
+
+bool StringBase::operator==(StringBase const& other) const
+{
+    if (is_short_string())
+        return m_data == other.m_data;
+    return bytes() == other.bytes();
+}
+
 }

AK/StringBase.h

@@ -45,6 +45,12 @@ public:
     // NOTE: This is primarily interesting to unit tests.
     [[nodiscard]] bool is_short_string() const;
 
+    // Returns the underlying UTF-8 encoded bytes.
+    // NOTE: There is no guarantee about null-termination.
+    [[nodiscard]] ReadonlyBytes bytes() const;
+
+    [[nodiscard]] bool operator==(StringBase const&) const;
+
 protected:
     // NOTE: If the least significant bit of the pointer is set, this is a short string.
     static constexpr uintptr_t SHORT_STRING_FLAG = 1;