src/java.base/share/classes/java/lang/String.java

*** 26,10 ***
--- 26,12 ---
  package java.lang;
  
  import java.io.ObjectStreamField;
  import java.io.UnsupportedEncodingException;
  import java.lang.annotation.Native;
+ import java.lang.foreign.MemorySegment;
+ import java.lang.foreign.ValueLayout;
  import java.lang.invoke.MethodHandles;
  import java.lang.constant.Constable;
  import java.lang.constant.ConstantDesc;
  import java.nio.ByteBuffer;
  import java.nio.CharBuffer;

*** 1834,10 ***
--- 1836,25 ---
       */
      public byte[] getBytes() {
          return encode(Charset.defaultCharset(), coder(), value);
      }
  
+     boolean bytesCompatible(Charset charset) {
+         if (isLatin1()) {
+             if (charset == ISO_8859_1.INSTANCE) {
+                 return true; // ok, same encoding
+             } else if (charset == UTF_8.INSTANCE || charset == US_ASCII.INSTANCE) {
+                 return !StringCoding.hasNegatives(value, 0, value.length); // ok, if ASCII-compatible
+             }
+         }
+         return false;
+     }
+ 
+     void copyToSegmentRaw(MemorySegment segment, long offset) {
+         MemorySegment.copy(value, 0, segment, ValueLayout.JAVA_BYTE, offset, value.length);
+     }
+ 
      /**
       * Compares this string to the specified object.  The result is {@code
       * true} if and only if the argument is not {@code null} and is a {@code
       * String} object that represents the same sequence of characters as this
       * object.