valid()

constexpr bool valid ( ) const

constexprnoexcept

Checks whether the object holds a valid UTF-8 character value or a special value used to indicate that the object is not associated with any character.

Returns

true, if the object carries attributes of a valid UTF-8 multi-byte character or false otherwise.

If the method returns false, this can either mean, that a valid multi-byte UTF-8 character has not been assigned to the u8_ch_data object, or that the UTF-8 character assigned to this has an invalid encoding as defined by the Unicode 11.0 standard.