Trait RefFromRow 

pub trait RefFromRow<'buf>: Sized {
    // Required method
    fn ref_from_row(
        cols: &[ColumnDefinition<'_>],
        row: BinaryRowPayload<'buf>,
    ) -> Result<&'buf Self>;
}

Trait for zero-copy decoding of a row into a fixed-size struct.

Unlike FromRow, this trait returns a reference directly into the buffer without any copying or allocation. This requires:

1. All fields have fixed wire sizes (implement FixedWireSize)
2. No NULL values (columns must be NOT NULL)
3. Struct has #[repr(C, packed)] layout

The derive macro generates zerocopy trait implementations automatically.

Compile-fail tests

Missing #[repr(C, packed)]:

use zero_mysql::ref_row::I32LE;
use zero_mysql_derive::RefFromRow;

#[derive(RefFromRow)]
struct Invalid {
    value: I32LE,
}

Native integer types (must use little-endian wrappers):

use zero_mysql_derive::RefFromRow;

#[derive(RefFromRow)]
#[repr(C, packed)]
struct Invalid {
    value: i64,
}

String fields are not allowed:

use zero_mysql_derive::RefFromRow;

#[derive(RefFromRow)]
#[repr(C, packed)]
struct Invalid {
    name: String,
}

Vec fields are not allowed:

use zero_mysql_derive::RefFromRow;

#[derive(RefFromRow)]
#[repr(C, packed)]
struct Invalid {
    data: Vec<u8>,
}

Required Methods

fn ref_from_row( cols: &[ColumnDefinition<'_>], row: BinaryRowPayload<'buf>, ) -> Result<&'buf Self>

Decode a row as a zero-copy reference.

Errors

Returns an error if:

• The row data size doesn’t match the struct size
• Any column is NULL (RefFromRow doesn’t support NULL)

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.

Implementors