[ Version ( since = "1.20" ) ]
public const Glyph GLYPH_INVALID_INPUT
The GLYPH_INVALID_INPUT macro represents a Glyph value that has a special meaning of invalid input.
Layout produces one such glyph per invalid input UTF-8 byte and such a glyph is rendered as a crossed box.
Note that this value is defined such that it has the GLYPH_UNKNOWN_FLAG on.