Commonize Char.titlecaseChar() and Char.titlecase() #KT-44369

libraries/stdlib/src/kotlin/text/Char.kt

@@ -193,6 +193,33 @@ public expect fun Char.uppercaseChar(): Char
 @ExperimentalStdlibApi
 public expect fun Char.uppercase(): String
 
+/**
+ * Converts this character to title case using Unicode mapping rules of the invariant locale.
+ *
+ * This function performs one-to-one character mapping.
+ * To support one-to-many character mapping use the [titlecase] function.
+ * If this character has no mapping equivalent, the result of calling [uppercaseChar] is returned.
+ *
+ * @sample samples.text.Chars.titlecase
+ */
+@SinceKotlin("1.4")
+@ExperimentalStdlibApi
+public expect fun Char.titlecaseChar(): Char
+
+/**
+ * Converts this character to title case using Unicode mapping rules of the invariant locale.
+ *
+ * This function supports one-to-many character mapping, thus the length of the returned string can be greater than one.
+ * For example, `'\uFB00'.titlecase()` returns `"\u0046\u0066"`,
+ * where `'\uFB00'` is the LATIN SMALL LIGATURE FF character (`ff`).
+ * If this character has no title case mapping, the result of [uppercase] is returned instead.
+ *
+ * @sample samples.text.Chars.titlecase
+ */
+@SinceKotlin("1.4")
+@ExperimentalStdlibApi
+public fun Char.titlecase(): String = titlecaseImpl()
+
 /**
  * Concatenates this Char and a String.
  *