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Utilities

Decimal Numbers

.. doxygenclass:: arrow::BasicDecimal128
   :members:


.. doxygenclass:: arrow::Decimal128
   :members:


.. doxygenclass:: arrow::BasicDecimal256
   :members:


.. doxygenclass:: arrow::Decimal256
   :members:

Iterators

.. doxygenclass:: arrow::Iterator
   :members:


.. doxygenclass:: arrow::VectorIterator
   :members:

Comparison

.. doxygenclass:: arrow::EqualOptions
   :members:

Compression

.. doxygenenum:: arrow::Compression::type


.. doxygenclass:: arrow::util::Codec
   :members:


.. doxygenclass:: arrow::util::Compressor
   :members:


.. doxygenclass:: arrow::util::Decompressor
   :members:

Visitors

.. doxygenfunction:: arrow::VisitTypeInline
   :project: arrow_cpp


.. doxygenfunction:: arrow::VisitTypeIdInline
   :project: arrow_cpp


.. doxygenfunction:: arrow::VisitScalarInline
   :project: arrow_cpp


.. doxygenfunction:: arrow::VisitArrayInline
   :project: arrow_cpp

Type Traits

These types provide relationships between Arrow types at compile time. :cpp:type:`TypeTraits` maps Arrow DataTypes to other types, and :cpp:type:`CTypeTraits` maps C types to Arrow types.

TypeTraits

Each specialized type defines the following associated types:

.. cpp:type:: TypeTraits::ArrayType

   Corresponding :doc:`Arrow array type <./array>`


.. cpp:type:: TypeTraits::BuilderType

   Corresponding :doc:`array builder type <./builder>`


.. cpp:type:: TypeTraits::ScalarType

   Corresponding :doc:`Arrow scalar type <./scalar>`


.. cpp:var:: bool TypeTraits::is_parameter_free

   Whether the type has any type parameters, such as field types in nested types
   or scale and precision in decimal types.

In addition, the following are defined for many but not all of the types:

.. cpp:type:: TypeTraits::CType

   Corresponding C type. For example, ``int64_t`` for ``Int64Array``.


.. cpp:type:: TypeTraits::TensorType

   Corresponding :doc:`Arrow tensor type <./tensor>`


.. cpp:function:: static inline constexpr int64_t bytes_required(int64_t elements)

   Return the number of bytes required for given number of elements. Defined for
   types with a fixed size.


.. cpp:function:: static inline std::shared_ptr<DataType> TypeTraits::type_singleton()

   For types where is_parameter_free is true, returns an instance of the data type.



.. doxygengroup:: type-traits
   :content-only:
   :members:
   :undoc-members:

CTypeTraits

Each specialized type defines the following associated types:

.. cpp:type:: CTypeTraits::ArrowType

   Corresponding :doc:`Arrow type <./datatype>`


.. doxygengroup:: c-type-traits
   :content-only:
   :members:
   :undoc-members:

Type Predicates

Type predicates that can be used with templates. Predicates of the form is_XXX resolve to constant boolean values, while predicates of the form enable_if_XXX resolve to the second type parameter R if the first parameter T passes the test.

Example usage:

template<typename TypeClass>
arrow::enable_if_number<TypeClass, RETURN_TYPE> MyFunction(const TypeClass& type) {
  ..
}

template<typename ArrayType, typename TypeClass=ArrayType::TypeClass>
arrow::enable_if_number<TypeClass, RETURN_TYPE> MyFunction(const ArrayType& array) {
  ..
}
.. doxygengroup:: type-predicates
   :content-only:
   :members:
   :undoc-members:

Runtime Type Predicates

Type predicates that can be applied at runtime.

.. doxygengroup:: runtime-type-predicates
   :content-only:
   :members:
   :undoc-members: