//! Traits linking Rust types to SQL types.

use std::fmt::{Debug, Display};

use crate::database::Database;

#[cfg(feature = "uuid")]

#[cfg_attr(docsrs, doc(cfg(feature = "uuid")))]

pub use uuid::Uuid;

#[cfg(feature = "chrono")]

#[cfg_attr(docsrs, doc(cfg(feature = "chrono")))]

pub mod chrono {

pub use chrono::{DateTime, NaiveDate, NaiveDateTime, NaiveTime, Utc};

}

pub trait TypeInfo: Debug + Display + Clone {

/// Compares type information to determine if `other` is compatible at the Rust level

/// with `self`.

fn compatible(&self, other: &Self) -> bool;

}

/// Indicates that a SQL type is supported for a database.

pub trait Type<DB>

where

DB: Database,

{

/// Returns the canonical type information on the database for the type `T`.

fn type_info() -> DB::TypeInfo;

}

// For references to types in Rust, the underlying SQL type information

// is equivalent

impl<T: ?Sized, DB> Type<DB> for &'_ T

where

DB: Database,

T: Type<DB>,

{

fn type_info() -> DB::TypeInfo {

<T as Type<DB>>::type_info()

}

}

// For optional types in Rust, the underlying SQL type information

// is equivalent

impl<T, DB> Type<DB> for Option<T>

where

DB: Database,

T: Type<DB>,

{

fn type_info() -> DB::TypeInfo {

<T as Type<DB>>::type_info()

}

}