Why there is no try_from attribute for sqlx::Type macro?

[gyzerok]

Hello there!

In my code I am actively using parse dont validate meaning I use newtype pattern extensively to embed data constraints into my domain types.

Here is a trivial example of this:

#[derive(Debug, Clone, PartialEq, Serialize)]
pub struct Username(String);

#[derive(Debug, thiserror::Error)]
#[error("invalid username")]
pub struct ParseUsernameError;

impl TryFrom<String> for Username {
    type Error = ParseUsernameError;

    fn try_from(value: String) -> Result<Self, Self::Error> {
        if value.len() > 100 {
            return Err(ParseUsernameError);
        }

        Ok(Self(value))
    }
}

impl From<Username> for String {
  fn from(value: Username) -> Self {
    value.0
  }
}

And I was wondering what is the reason sqlx::Type macro won't allow me to reuse my existing TryFrom and From implementations? It is available in sqlx::FromRow, but not here.

[gyzerok]

For the future readers I found the discussion about it here: #2648

[tomknig]

I am such future reader. Thank you for the reference!