Struct Username 

pub struct Username {
    pub message: String,
    pub min_length: usize,
    pub max_length: usize,
    pub allow_dots: bool,
    pub allow_hyphens: bool,
}

Validates that a value is a valid username.

Rules:

• Only alphanumeric, underscores, hyphens, and dots
• Must start with a letter or digit
• Cannot end with a special character
• No consecutive special characters
• Length between min and max

Fields

message: String

min_length: usize

max_length: usize

allow_dots: bool

allow_hyphens: bool

Implementations

impl Username

pub fn new() -> Self

pub fn with_message(self, message: impl Into<String>) -> Self

pub fn min_length(self, min: usize) -> Self

pub fn max_length(self, max: usize) -> Self

pub fn allow_dots(self, allow: bool) -> Self

pub fn allow_hyphens(self, allow: bool) -> Self

Trait Implementations

impl Constraint for Username

fn validate(&self, value: &str) -> ConstraintResult

fn name(&self) -> &'static str

impl Default for Username

fn default() -> Self

Returns the “default value” for a type.