error[E0512]: cannot transmute between types of different sizes, or dependently-sized types

[schooldanlp6]

error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
--> directory/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.3.12/src/sockaddr.rs:176:9
|
176 | mem::transmute::<SocketAddrV4, sockaddr_in>(v4);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: source type: SocketAddrV4 (48 bits)
= note: target type: SOCKADDR_IN (128 bits)

Compiling time v0.1.42
For more information about this error, try rustc --explain E0512.
error: could not compile socket2 due to previous error
warning: build failed, waiting for other jobs to finish...

it crashes for two different sized things that where tried to be merged together?