diff options
Diffstat (limited to 'boost/gil/extension/dynamic_image/variant.hpp')
| -rw-r--r-- | boost/gil/extension/dynamic_image/variant.hpp | 81 |
1 files changed, 36 insertions, 45 deletions
diff --git a/boost/gil/extension/dynamic_image/variant.hpp b/boost/gil/extension/dynamic_image/variant.hpp index 1ab53b549d..a0eb0f85db 100644 --- a/boost/gil/extension/dynamic_image/variant.hpp +++ b/boost/gil/extension/dynamic_image/variant.hpp @@ -1,46 +1,37 @@ -/* - Copyright 2005-2007 Adobe Systems Incorporated - - Use, modification and distribution are subject to the Boost Software License, - Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at - http://www.boost.org/LICENSE_1_0.txt). - - See http://opensource.adobe.com/gil for most recent version including documentation. -*/ - -/*************************************************************************************************/ +// +// Copyright 2005-2007 Adobe Systems Incorporated +// +// Distributed under the Boost Software License, Version 1.0 +// See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt +// +#ifndef BOOST_GIL_EXTENSION_DYNAMIC_IMAGE_VARIANT_HPP +#define BOOST_GIL_EXTENSION_DYNAMIC_IMAGE_VARIANT_HPP -#ifndef GIL_DYNAMICIMAGE_VARIANT_HPP -#define GIL_DYNAMICIMAGE_VARIANT_HPP +// TODO: Replace with C++17 std::variant? -//////////////////////////////////////////////////////////////////////////////////////// -/// \file -/// \brief Support for run-time instantiated types -/// \author Lubomir Bourdev and Hailin Jin \n -/// Adobe Systems Incorporated -/// \date 2005-2007 \n Last updated on September 18, 2007 -/// -//////////////////////////////////////////////////////////////////////////////////////// +#include <boost/gil/utilities.hpp> -#include "../../gil_config.hpp" -#include "../../utilities.hpp" -#include <cstddef> -#include <cassert> -#include <algorithm> -#include <typeinfo> #include <boost/bind.hpp> -#include <boost/utility/enable_if.hpp> +#include <boost/mpl/at.hpp> #include <boost/mpl/bool.hpp> -#include <boost/mpl/transform.hpp> +#include <boost/mpl/fold.hpp> +#include <boost/mpl/max.hpp> #include <boost/mpl/size.hpp> #include <boost/mpl/sizeof.hpp> -#include <boost/mpl/max.hpp> -#include <boost/mpl/at.hpp> -#include <boost/mpl/fold.hpp> +#include <boost/mpl/transform.hpp> +#include <boost/utility/enable_if.hpp> + +#include <algorithm> +#include <cassert> +#include <cstddef> +#include <typeinfo> namespace boost { namespace gil { -namespace detail { +// Support for run-time instantiated types + +namespace detail { template <typename Types, typename T> struct type_to_index; template <typename Op, typename T> struct reduce; struct destructor_op { @@ -66,21 +57,21 @@ It would be difficult to write a function that reads an image from file preservi type of the return value is only available at run time. It would be difficult to store images of different color spaces in the same container or apply operations on them uniformly. -The variant class addresses this deficiency. It allows for run-time instantiation of a class from a given set of allowed classes -specified at compile time. For example, the set of allowed classes may include 8-bit and 16-bit RGB and CMYK images. Such a variant +The variant class addresses this deficiency. It allows for run-time instantiation of a class from a given set of allowed classes +specified at compile time. For example, the set of allowed classes may include 8-bit and 16-bit RGB and CMYK images. Such a variant can be constructed with rgb8_image_t and then assigned a cmyk16_image_t. -The variant has a templated constructor, which allows us to construct it with any concrete type instantiation. It can also perform a generic +The variant has a templated constructor, which allows us to construct it with any concrete type instantiation. It can also perform a generic operation on the concrete type via a call to apply_operation. The operation must be provided as a function object whose application operator has a single parameter which can be instantiated with any of the allowed types of the variant. -variant breaks down the instantiated type into a non-templated underlying base type and a unique instantiation +variant breaks down the instantiated type into a non-templated underlying base type and a unique instantiation type identifier. In the most common implementation the concrete instantiation in stored 'in-place' - in 'bits_t'. bits_t contains sufficient space to fit the largest of the instantiated objects. GIL's variant is similar to boost::variant in spirit (hence we borrow the name from there) but it differs in several ways from the current boost implementation. Most notably, it does not take a variable number of template parameters but a single parameter defining the type enumeration. As -such it can be used more effectively in generic code. +such it can be used more effectively in generic code. The Types parameter specifies the set of allowable types. It models MPL Random Access Container */ @@ -162,7 +153,7 @@ namespace detail { struct equal_to_fn { const Bits& _dst; equal_to_fn(const Bits& dst) : _dst(dst) {} - + typedef bool result_type; template <typename T> result_type operator()(const T& x) const { return x==*gil_reinterpret_cast_c<const T*>(&_dst); @@ -178,21 +169,21 @@ namespace detail { } // When doSwap is true, swaps obj with the contents of the variant. obj will contain default-constructed instance after the call -template <typename Types> +template <typename Types> template <typename T> variant<Types>::variant(T& obj, bool do_swap) { - _index=type_id<T>(); - if (_index==NUM_TYPES) throw std::bad_cast(); + _index=type_id<T>(); + if (_index==NUM_TYPES) throw std::bad_cast(); if (do_swap) { new(&_bits) T(); // default construct swap(obj, *gil_reinterpret_cast<T*>(&_bits)); - } else + } else detail::copy_construct_in_place(const_cast<const T&>(obj), _bits); } -template <typename Types> +template <typename Types> void swap(variant<Types>& x, variant<Types>& y) { - std::swap(x._bits,y._bits); + std::swap(x._bits,y._bits); std::swap(x._index, y._index); } |