.. _file_include_reduce.hpp:

File reduce.hpp
===============

|exhale_lsh| :ref:`Parent directory <dir_include>` (``include``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS



Compile-time folds over ``HasStaticSize`` types. 



.. contents:: Contents
   :local:
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Definition (``include/reduce.hpp``)
-----------------------------------


.. toctree::
   :maxdepth: 1

   program_listing_file_include_reduce.hpp.rst



Detailed Description
--------------------

Folds a pack of types that expose a static size (via the ``HasStaticSize`` predicate) using a user-supplied binary meta-op on ``std::size_t``. The public API is the ``{reduce_sizes_t, reduce_sizes_v}`` pair, plus ``Sum{,_v}``. Complexity is linear in the number of types.


Example

structA{staticconstexprstd::size_tsize=3;};
structB{staticconstexprstd::size_tsize=5;};
static_assert(ctql::Sum_v<A,B>==8);


Works at compile time only; results are ``std::integral_constant<size_t, ...>`` or a value thereof. 







Includes
--------


- ``htlist.hpp`` (:ref:`file_include_htlist.hpp`)

- ``predicates.hpp`` (:ref:`file_include_predicates.hpp`)

- ``type_traits``






Namespaces
----------


- :ref:`namespace_ctql`


Typedefs
--------


- :ref:`exhale_typedef_reduce_8hpp_1a31be6bb9f5bad4a475568bcd27c180fd`

- :ref:`exhale_typedef_reduce_8hpp_1a9437db4ee3b2145a04b47c61e2880c41`


Variables
---------


- :ref:`exhale_variable_reduce_8hpp_1ab9131c047a1091768ec414c1f9ac70bc`

- :ref:`exhale_variable_reduce_8hpp_1a051256625001aa3b8da2c9127c602206`