Improve documentation generation

Fix xs::select output and add forgotten conversion functions

docs/source/api/batch_manip.rst

@@ -9,16 +9,18 @@ Conditional expression
 
 .. toctree::
 
-+---------------------------------------------+---------------------------------------------------+
-| :ref:`select <select-function-reference>`   | conditional selection                              |
-+---------------------------------------------+---------------------------------------------------+
++-------------------------------------------------+---------------------------------------------------+
+| :ref:`select <select-function-reference-dyn>`   | conditional selection with dynamic mask           |
++-------------------------------------------------+---------------------------------------------------+
+| :ref:`select <select-function-reference>`       | conditional selection with constant mask          |
++-------------------------------------------------+---------------------------------------------------+
 
 
-.. _select-function-reference:
-.. doxygenfunction:: xsimd::select(batch_bool<T, A> const&, batch<T, A> const&, batch<T, A> const&)
+.. _select-function-reference-dyn:
+.. doxygenfunction:: select(batch_bool<T, A> const &cond, batch<T, A> const &true_br, batch<T, A> const &false_br) noexcept
    :project: xsimd
 
 .. _select-function-reference:
-.. doxygenfunction:: xsimd::select(batch_bool_constant<T, A> const&, batch<T, A> const&, batch<T, A> const&)
+.. doxygenfunction:: select(batch_bool_constant<batch<T, A>, Values...> const &cond, batch<T, A> const &true_br, batch<T, A> const &false_br) noexcept
    :project: xsimd
 

include/xsimd/types/xsimd_api.hpp

@@ -207,7 +207,7 @@ namespace xsimd
      *
      * Perform a static_cast from \c T_in to \c T_out on \c \c x.
      * @param x batch_bool of \c T_in
-     * @return \c x casted to \c T_out
+     * @return \c x cast to \c T_out
      */
     template <class T_out, class T_in, class A>
     inline batch_bool<T_out, A> batch_bool_cast(batch_bool<T_in, A> const& x) noexcept
@@ -223,7 +223,7 @@ namespace xsimd
      *
      * Perform a static_cast from \c T_in to \c T_out on \c \c x.
      * @param x batch of \c T_in
-     * @return \c x casted to \c T_out
+     * @return \c x cast to \c T_out
      */
     template <class T_out, class T_in, class A>
     inline batch<T_out, A> batch_cast(batch<T_in, A> const& x) noexcept
@@ -2174,7 +2174,16 @@ namespace xsimd
         return kernel::zip_lo<A>(x, y, A {});
     }
 
-    // bitwise_cast
+    /**
+     * @ingroup batch_conversion
+     *
+     * Cast a \c batch_bool of \c T into a \c batch of the same type using the
+     * following rule: if an element of \c self is true, it maps to -1 in the
+     * returned integral batch, otherwise it maps to 0.
+     *
+     * @param self batch_bool of \c T
+     * @return \c self cast to a \c batch of \c T
+     */
     template <class T, class A, typename std::enable_if<std::is_integral<T>::value, int>::type = 3>
     inline batch<T, A> bitwise_cast(batch_bool<T, A> const& self) noexcept
     {