validateString

fnstring validateString(string str, size_t min_length = 0, size_t max_length = 0, string entity_name = "String")

Checks if a string falls within the specified length range.

fnbool validateString(R)(ref R error_sink, string str, size_t min_length = 0, size_t max_length = 0, string entity_name = "String") if (isOutputRange!(R, char))

ditto