ceph/src/boost/libs/gil/include/boost/gil/extension/io/dynamic_io.hpp

   1 /*
   2     Copyright 2005-2007 Adobe Systems Incorporated
   3
   4     Use, modification and distribution are subject to the Boost Software License,
   5     Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   6     http://www.boost.org/LICENSE_1_0.txt).
   7
   8     See http://opensource.adobe.com/gil for most recent version including documentation.
   9 */
  10 /*************************************************************************************************/
  11
  12 #ifndef GIL_DYNAMIC_IO_H
  13 #define GIL_DYNAMIC_IO_H
  14
  15 /// \file
  16 /// \brief  Generic io functions for dealing with dynamic images
  17 //
  18 /// \author Hailin Jin and Lubomir Bourdev \n
  19 ///         Adobe Systems Incorporated
  20 /// \date   2005-2007 \n Last updated May 30, 2006
  21
  22 #include <boost/mpl/at.hpp>
  23 #include <boost/mpl/size.hpp>
  24 #include "../../gil_config.hpp"
  25 #include "io_error.hpp"
  26 #include "../dynamic_image/any_image.hpp"
  27
  28 namespace boost { namespace gil {
  29
  30 namespace detail {
  31
  32 template <long N>
  33 struct construct_matched_t {
  34     template <typename Images,typename Pred>
  35     static bool apply(any_image<Images>& im,Pred pred) {
  36         if (pred.template apply<typename mpl::at_c<Images,N-1>::type>()) {
  37             typename mpl::at_c<Images,N-1>::type x;
  38             im.move_in(x);
  39             return true;
  40         } else return construct_matched_t<N-1>::apply(im,pred);
  41     }
  42 };
  43 template <>
  44 struct construct_matched_t<0> {
  45     template <typename Images,typename Pred>
  46     static bool apply(any_image<Images>&,Pred) {return false;}
  47 };
  48
  49 // A function object that can be passed to apply_operation.
  50 // Given a predicate IsSupported taking a view type and returning an MPL boolean,
  51 // calls the apply method of OpClass with the view if the given view IsSupported, or throws an exception otherwise
  52 template <typename IsSupported, typename OpClass>
  53 class dynamic_io_fnobj {
  54     OpClass* _op;
  55
  56     template <typename View>
  57     void apply(const View& view,mpl::true_ ) {_op->apply(view);}
  58     template <typename View>
  59     void apply(const View& view,mpl::false_) {io_error("dynamic_io: unsupported view type for the given file format");}
  60 public:
  61     dynamic_io_fnobj(OpClass* op) : _op(op) {}
  62
  63     typedef void result_type;
  64
  65     template <typename View>
  66     void operator()(const View& view) {apply(view,typename IsSupported::template apply<View>::type());}
  67 };
  68
  69 } // namespace detail
  70
  71 /// \brief Within the any_image, constructs an image with the given dimensions
  72 ///        and a type that satisfies the given predicate
  73 template <typename Images,typename Pred>
  74 inline bool construct_matched(any_image<Images>& im,Pred pred) {
  75     return detail::construct_matched_t<mpl::size<Images>::value>::apply(im,pred);
  76 }
  77
  78 } }  // namespace boost::gil
  79
  80 #endif