73 lines
1.6 KiB
Rust
73 lines
1.6 KiB
Rust
use serde::{de::Error, Deserialize};
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use std::{
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fmt::Display,
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ops::{Deref, DerefMut},
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str::FromStr,
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};
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#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, serde::Serialize)]
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#[serde(transparent)]
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pub(crate) struct Optional<T> {
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#[serde(skip_serializing_if = "Option::is_none")]
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inner: Option<T>,
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}
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impl<T> Deref for Optional<T> {
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type Target = Option<T>;
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fn deref(&self) -> &Self::Target {
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&self.inner
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}
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}
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impl<T> DerefMut for Optional<T> {
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.inner
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}
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}
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impl<T> From<Option<T>> for Optional<T> {
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fn from(inner: Option<T>) -> Self {
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Optional { inner }
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}
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}
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impl<T> From<Optional<T>> for Option<T> {
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fn from(e: Optional<T>) -> Self {
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e.inner
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}
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}
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impl<T> Optional<T> {
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pub fn as_ref(&self) -> Option<&T> {
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self.inner.as_ref()
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}
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pub fn as_deref(&self) -> Option<&T::Target>
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where
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T: Deref,
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{
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self.inner.as_deref()
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}
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}
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impl<'de, T> Deserialize<'de> for Optional<T>
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where
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T: FromStr,
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T::Err: Display,
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{
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fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
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where
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D: serde::Deserializer<'de>,
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{
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let s: Option<String> = Deserialize::<'de>::deserialize(deserializer)?;
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match s.as_deref().map(|s| s.trim()) {
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None | Some("") => Ok(Optional { inner: None }),
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Some(s) => T::from_str(&s)
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.map_err(D::Error::custom)
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.map(Some)
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.map(|inner| Optional { inner }),
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}
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}
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}
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