use crate::error::Error;
pub fn apply<T: Utf16CodeUnits>(v: &T, (min, max): (usize, usize)) -> Result<(), Error> {
v.validate_num_code_units(min, max)
}
pub trait Utf16CodeUnits {
fn validate_num_code_units(&self, min: usize, max: usize) -> Result<(), Error>;
}
impl<T: HasUtf16CodeUnits> Utf16CodeUnits for T {
fn validate_num_code_units(&self, min: usize, max: usize) -> Result<(), Error> {
super::check_len(self.num_code_units(), min, max)
}
}
impl<T: Utf16CodeUnits> Utf16CodeUnits for Option<T> {
fn validate_num_code_units(&self, min: usize, max: usize) -> Result<(), Error> {
match self {
Some(v) => v.validate_num_code_units(min, max),
None => Ok(()),
}
}
}
pub trait HasUtf16CodeUnits {
fn num_code_units(&self) -> usize;
}
macro_rules! impl_str {
($(in<$lifetime:lifetime>)? $T:ty) => {
impl<$($lifetime)?> HasUtf16CodeUnits for $T {
fn num_code_units(&self) -> usize {
self.encode_utf16().count()
}
}
};
}
impl_str!(std::string::String);
impl_str!(in<'a> &'a std::string::String);
impl_str!(in<'a> &'a str);
impl_str!(in<'a> std::borrow::Cow<'a, str>);
impl_str!(std::rc::Rc<str>);
impl_str!(std::sync::Arc<str>);
impl_str!(std::boxed::Box<str>);