1 pub struct Nullable<T: NotNull>(T);
5 pub trait IntoNullable {
9 impl<T: NotNull> IntoNullable for T {
10 type Nullable = Nullable<T>;
13 impl<T: NotNull> IntoNullable for Nullable<T> {
14 type Nullable = Nullable<T>;
17 pub trait Expression {
21 pub trait Column: Expression {}
23 #[derive(Debug, Copy, Clone)]
24 //~^ ERROR the trait bound `<Col as Expression>::SqlType: NotNull` is not satisfied
25 pub enum ColumnInsertValue<Col, Expr> where
27 Expr: Expression<SqlType=<Col::SqlType as IntoNullable>::Nullable>,
29 Expression(Col, Expr),