Method downcast_dict

arrow-array/src/array/dictionary_array.rs:432–438

Downcast this dictionary to a [`TypedDictionaryArray`] ``` use arrow_array::{Array, ArrayAccessor, DictionaryArray, StringArray, types::Int32Type}; let orig = [Some("a"), Some("b"), None]; let dictionary = DictionaryArray:: ::from_iter(orig); let typed = dictionary.downcast_dict:: ().unwrap(); assert_eq!(typed.value(0), "a"); assert_eq!(typed.value(1), "b"); assert!(typed.i

(&self)

    /// ```
    ///
    pub fn downcast_dict<V: 'static>(&self) -> Option<TypedDictionaryArray<'_, K, V>> {
        let values = self.values.as_any().downcast_ref()?;
        Some(TypedDictionaryArray {
            dictionary: self,
            values,
        })
    }

    /// Returns a new dictionary with the same keys as the current instance
    /// but with a different set of dictionary values