StringRef is a reference to a string owned by something else.
bool is_unset(StringRef value)
True for what Home Assistant reports when there is no value: "None" for an attribute that is not set,...
PROGMEM_STRING_TABLE(UnsetValues, "None", "unavailable", "unknown")
int16_t progmem_string_table_find(const char *value, size_t len)
The index of the string value (len bytes, in RAM) in a PROGMEM_STRING_TABLE, or -1 when it is not one...