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use crate::database::{Database, HasValueRef};
use crate::decode::Decode;
use crate::error::{mismatched_types, Error};
use crate::type_info::TypeInfo;
use crate::types::Type;
use std::borrow::Cow;
pub trait Value {
type Database: Database;
fn as_ref(&self) -> <Self::Database as HasValueRef<'_>>::ValueRef;
fn type_info(&self) -> Cow<'_, <Self::Database as Database>::TypeInfo>;
fn is_null(&self) -> bool;
#[inline]
fn decode<'r, T>(&'r self) -> T
where
T: Decode<'r, Self::Database> + Type<Self::Database>,
{
self.try_decode::<T>().unwrap()
}
#[inline]
fn decode_unchecked<'r, T>(&'r self) -> T
where
T: Decode<'r, Self::Database>,
{
self.try_decode_unchecked::<T>().unwrap()
}
#[inline]
fn try_decode<'r, T>(&'r self) -> Result<T, Error>
where
T: Decode<'r, Self::Database> + Type<Self::Database>,
{
if !self.is_null() {
let ty = self.type_info();
if !ty.is_null() && !T::compatible(&ty) {
return Err(Error::Decode(mismatched_types::<Self::Database, T>(&ty)));
}
}
self.try_decode_unchecked()
}
#[inline]
fn try_decode_unchecked<'r, T>(&'r self) -> Result<T, Error>
where
T: Decode<'r, Self::Database>,
{
T::decode(self.as_ref()).map_err(Error::Decode)
}
}
pub trait ValueRef<'r>: Sized {
type Database: Database;
fn to_owned(&self) -> <Self::Database as Database>::Value;
fn type_info(&self) -> Cow<'_, <Self::Database as Database>::TypeInfo>;
fn is_null(&self) -> bool;
}