pub trait StaticallySizedRow<ST, DB: Backend>: FromSqlRow<ST, DB> {
    const FIELD_COUNT: usize;
Expand description

A marker trait indicating that the corresponding type consumes a static at compile time known number of field

There is normally no need to implement this trait. Diesel provides wild card impls for all types that implement FromSql<ST, DB> or Queryable<ST, DB> where the size of ST is known

Required Associated Constants§


const FIELD_COUNT: usize

The number of fields that this type will consume.

Object Safety§

This trait is not object safe.



impl<T, ST, DB> StaticallySizedRow<ST, DB> for T
where ST: SqlTypeOrSelectable + TupleSize, T: Queryable<ST, DB>, DB: Backend,


const FIELD_COUNT: usize = <ST as crate::util::TupleSize>::SIZE