Method prefers_self

src/sql/src/func.rs:793–799

Is `self` the preferred parameter type for its `TypeCategory`?

(&self)

    /// Is `self` the preferred parameter type for its `TypeCategory`?
    fn prefers_self(&self) -> bool {
        if let Some(pt) = TypeCategory::from_param(self).preferred_type() {
            *self == pt
        } else {
            false
        }
    }

    fn is_polymorphic(&self) -> bool {
        use ParamType::*;