feat: compile-time assoc of rust <> postgres types

postgres-types/src/lib.rs

@@ -276,6 +276,101 @@ pub mod private;
 mod special;
 mod type_gen;
 
+/// compile-time association between rust type
+/// and runtime postgres [`Type`]
+pub trait Typed {
+  /// What [`Type`] is `Self`?
+  const TYPE: Type;
+}
+
+impl Typed for IpAddr {
+  const TYPE: Type = Type::INET;
+}
+
+impl Typed for SystemTime {
+  const TYPE: Type = Type::TIMESTAMP;
+}
+
+impl Typed for &[&str] {
+  const TYPE: Type = Type::TEXT_ARRAY;
+}
+
+impl Typed for &[String] {
+  const TYPE: Type = Type::TEXT_ARRAY;
+}
+
+impl Typed for &[bool] {
+  const TYPE: Type = Type::BOOL_ARRAY;
+}
+
+impl Typed for bool {
+  const TYPE: Type = Type::BOOL;
+}
+
+impl Typed for &str {
+  const TYPE: Type = Type::TEXT;
+}
+
+impl Typed for String {
+  const TYPE: Type = Type::TEXT;
+}
+
+impl Typed for i8 {
+  const TYPE: Type = Type::CHAR;
+}
+
+impl Typed for i16 {
+  const TYPE: Type = Type::INT2;
+}
+
+impl Typed for i32 {
+  const TYPE: Type = Type::INT4;
+}
+
+impl Typed for i64 {
+  const TYPE: Type = Type::INT8;
+}
+
+impl Typed for u32 {
+  const TYPE: Type = Type::OID;
+}
+
+impl Typed for f32 {
+  const TYPE: Type = Type::FLOAT4;
+}
+
+impl Typed for f64 {
+  const TYPE: Type = Type::FLOAT8;
+}
+
+impl Typed for &[i8] {
+  const TYPE: Type = Type::CHAR_ARRAY;
+}
+
+impl Typed for &[i16] {
+  const TYPE: Type = Type::INT2_ARRAY;
+}
+
+impl Typed for &[i32] {
+  const TYPE: Type = Type::INT4_ARRAY;
+}
+
+impl Typed for &[i64] {
+  const TYPE: Type = Type::INT8_ARRAY;
+}
+
+impl Typed for &[u32] {
+  const TYPE: Type = Type::OID_ARRAY;
+}
+
+impl Typed for &[f32] {
+  const TYPE: Type = Type::FLOAT4_ARRAY;
+}
+
+impl Typed for &[f64] {
+  const TYPE: Type = Type::FLOAT8_ARRAY;
+}
+
 /// A Postgres type.
 #[derive(PartialEq, Eq, Clone, Hash)]
 pub struct Type(Inner);