feat(core): add sqlx::RawValue

sqlx-core/src/raw_value.rs

@@ -0,0 +1,16 @@
+use std::any;
+
+use crate::database::HasRawValue;
+use crate::{decode, Database, Decode, TypeDecode, TypeInfo};
+
+// NOTE: Add decode() and decode_unchecked() to RawValue as provided methods
+//       once Rust has lazy normalization and/or GATs.
+pub trait RawValue<'r>: Sized {
+    type Database: Database;
+
+    /// Returns `true` if this value is the SQL `NULL`.
+    fn is_null(&self) -> bool;
+
+    /// Returns the type information for this value.
+    fn type_info(&self) -> &'r <Self::Database as Database>::TypeInfo;
+}