welds 0.4.23

An async ORM for (postgres, mssql, mysql, sqlite)
Documentation 
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// This is part of the fluent builder for queries.
// We are using it instead of Option so we can have slightly different behavior
//
// often you have a database that has null columns everywhere.
// If all you want to do is query, it would get very annoying have to deal will Some/None
// for everything that goes into the query. This allows for searching by
// .where_col(|x| x.name.equal("bla") )
// and not having to know if the DB column is null
//
// This is for writing sql only.

pub enum Optional<T> {
    Some(T),
    None,
}

pub trait HasSomeNone {
    fn is_none(&self) -> bool;
    fn is_some(&self) -> bool;
}

impl<T> HasSomeNone for Optional<T> {
    fn is_none(&self) -> bool {
        match self {
            Optional::Some(_) => false,
            Optional::None => true,
        }
    }
    fn is_some(&self) -> bool {
        match self {
            Optional::Some(_) => true,
            Optional::None => false,
        }
    }
}

impl<T> From<T> for Optional<T> {
    fn from(inner: T) -> Optional<T> {
        Optional::Some(inner)
    }
}

impl<T> From<Optional<T>> for Option<T> {
    fn from(opt: Optional<T>) -> Option<T> {
        match opt {
            Optional::Some(x) => Some(x),
            Optional::None => None,
        }
    }
}
impl<T> From<Option<T>> for Optional<T> {
    fn from(opt: Option<T>) -> Optional<T> {
        match opt {
            Option::Some(x) => Optional::Some(x),
            Option::None => Optional::None,
        }
    }
}

impl From<&str> for Optional<String> {
    fn from(inner: &str) -> Optional<String> {
        Optional::Some(inner.into())
    }
}
impl From<&String> for Optional<String> {
    fn from(inner: &String) -> Optional<String> {
        Optional::Some(inner.into())
    }
}

impl From<&Option<&str>> for Optional<String> {
    fn from(inner: &Option<&str>) -> Optional<String> {
        match inner {
            Option::Some(x) => Optional::Some(x.to_string()),
            Option::None => Optional::None,
        }
    }
}

impl From<&Option<String>> for Optional<String> {
    fn from(inner: &Option<String>) -> Optional<String> {
        match inner {
            Option::Some(x) => Optional::Some(x.clone()),
            Option::None => Optional::None,
        }
    }
}

impl<T> Clone for Optional<T>
where
    T: Clone,
{
    fn clone(&self) -> Self {
        match self {
            Optional::Some(x) => Optional::Some(x.clone()),
            Optional::None => Optional::None,
        }
    }
}