enum class error_handler_t { strict, replace, ignore };
This enumeration is used in the dump function to choose how to treat decoding errors while serializing a basic_json value. Three values are differentiated:
strict : throw a type_error exception in case of invalid UTF-8
replace : replace invalid UTF-8 sequences with U+FFFD (� REPLACEMENT CHARACTER)
ignore : ignore invalid UTF-8 sequences; all bytes are copied to the output unchanged