From 46f314103aa2eca5ab24e2e88de76344a25b85d2 Mon Sep 17 00:00:00 2001
From: Ryan Leckey <ryan@launchbadge.com>
Date: Thu, 18 Feb 2021 14:11:35 -0800
Subject: [PATCH] feat(core): add TypeEncode::compatible

---
 sqlx-core/src/type.rs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/sqlx-core/src/type.rs b/sqlx-core/src/type.rs
index 6a48c1f8..f3784401 100644
--- a/sqlx-core/src/type.rs
+++ b/sqlx-core/src/type.rs
@@ -33,11 +33,19 @@ pub trait Type<Db: Database> {
 
 #[allow(clippy::module_name_repetitions)]
 pub trait TypeEncode<Db: Database>: Type<Db> + Encode<Db> {
-    /// Returns the SQL type identifier that best hints to the database
-    /// at the incoming value for a bind parameter.
+    /// Returns the canonical SQL type identifier for this Rust type.
     #[allow(unused_variables)]
     fn type_id(&self, ty: &Db::TypeInfo) -> Db::TypeId;
 
+    /// Determines if this Rust type is compatible with the specified SQL type.
+    ///
+    /// To be compatible, the Rust type must support encoding _and_ decoding
+    /// from the specified SQL type.
+    ///
+    fn compatible(&self, ty: &Db::TypeInfo) -> bool {
+        ty.id() == self.type_id(ty)
+    }
+
     /// Returns the Rust type name of this.
     #[doc(hidden)]
     #[inline]