I'm using Golang 1.10 with Gin (I'm not sure the version, but I'm using just go get github.com/gin-gonic/gin, and I'm getting a runtime error that there is Undefined validation function on field Username.

This is my code

type User struct {
	Username string `json:"username" binding:"required,min=4,max=30,alphanumunicode"`
	Email    string `json:"email" binding:"required,email"`
	Password string `json:"password" binding:"required"`
}

And it is failing on alphanumunicode, as defined in the validation documentation.

It has failed on several other documented validation functions as well. Does gin limit to a subset of these validation functions?