pub trait WriteTuple<ST> {
// Required method
fn write_tuple<W: Write>(&self, out: &mut Output<'_, W, Pg>) -> Result;
}Expand description
Helper trait for writing tuples as named composite types
This trait is essentially ToSql<Record<ST>> for tuples.
While we can provide a valid body of to_sql,
PostgreSQL doesn’t allow the use of bind parameters for unnamed composite types.
For this reason, we avoid implementing ToSql directly.
This trait can be used by ToSql impls of named composite types.
§Example
#[derive(SqlType)]
#[postgres(type_name = "my_type")]
struct MyType;
#[derive(Debug)]
struct MyStruct<'a>(i32, &'a str);
impl<'a> ToSql<MyType, Pg> for MyStruct<'a> {
fn to_sql<W: Write>(&self, out: &mut Output<W, Pg>) -> serialize::Result {
WriteTuple::<(Integer, Text)>::write_tuple(
&(self.0, self.1),
out,
)
}
}Required Methods§
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.