use core::{fmt, marker::PhantomData};
use crate::{Field, SerializePartial};
pub trait SerializeFilter<T: ?Sized> {
fn skip(&self, field: Field<'_, T>) -> bool;
fn filtered_len(&self, len: Option<usize>) -> Option<usize>;
}
pub struct InverseFilter<'a, T, F = <T as SerializePartial<'a>>::Filter>
where
T: ?Sized + SerializePartial<'a>,
{
filter: F,
_ty: PhantomData<&'a T>,
}
impl<'a, T, F> SerializeFilter<T> for InverseFilter<'a, T, F>
where
T: ?Sized + SerializePartial<'a>,
F: SerializeFilter<T>,
{
fn skip(&self, field: Field<'_, T>) -> bool {
!self.filter.skip(field)
}
fn filtered_len(&self, len: Option<usize>) -> Option<usize> {
match (len, self.filter.filtered_len(len)) {
(Some(len), Some(filtered_len)) => Some(len - filtered_len),
_ => None,
}
}
}
impl<'a, T, F> InverseFilter<'a, T, F>
where
T: ?Sized + SerializePartial<'a>,
F: SerializeFilter<T>,
{
pub fn new(filter: F) -> Self {
Self {
filter,
_ty: PhantomData,
}
}
}
impl<'a, T, F> Clone for InverseFilter<'a, T, F>
where
T: ?Sized + SerializePartial<'a>,
F: Clone,
{
fn clone(&self) -> Self {
Self {
filter: self.filter.clone(),
_ty: PhantomData,
}
}
}
impl<'a, T, F> Copy for InverseFilter<'a, T, F>
where
T: ?Sized + SerializePartial<'a>,
F: Copy,
{
}
impl<'a, T, F> fmt::Debug for InverseFilter<'a, T, F>
where
T: ?Sized + SerializePartial<'a>,
F: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_tuple("InverseFilter").field(&self.filter).finish()
}
}