Ada Programming/Libraries/Ada.Strings.UTF Encoding.Wide Wide Strings

is a unit of the Predefined Language Environment since Ada 2012.

Specification
Pure Wide_Wide_Strings Encode Item          Wide_Wide_String Output_Scheme Encoding_Scheme Output_BOM    Boolean   False  UTF_String Encode Item       Wide_Wide_String Output_BOM Boolean   False  UTF_8_String Encode Item       Wide_Wide_String Output_BOM Boolean   False UTF_16_Wide_String Decode Item         UTF_String Input_Scheme Encoding_Scheme  Wide_Wide_String Decode Item UTF_8_String  Wide_Wide_String Decode Item UTF_16_Wide_String  Wide_Wide_String AdaStringsUTF_EncodingWide_Wide_Strings

Wikibook

 * Ada Programming/Libraries/Ada
 * Ada Programming/Libraries/Ada.Strings
 * Ada Programming/Libraries/Ada.Strings.UTF_Encoding