1///////////////////////////////////////////////////////////////////////////
2//
3// Copyright (c) 2012, Industrial Light & Magic, a division of Lucas
4// Digital Ltd. LLC
5//
6// All rights reserved.
7//
8// Redistribution and use in source and binary forms, with or without
9// modification, are permitted provided that the following conditions are
10// met:
11// * Redistributions of source code must retain the above copyright
12// notice, this list of conditions and the following disclaimer.
13// * Redistributions in binary form must reproduce the above
14// copyright notice, this list of conditions and the following disclaimer
15// in the documentation and/or other materials provided with the
16// distribution.
17// * Neither the name of Industrial Light & Magic nor the names of
18// its contributors may be used to endorse or promote products derived
19// from this software without specific prior written permission.
20//
21// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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27// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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31// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32//
33///////////////////////////////////////////////////////////////////////////
34
35#ifndef INCLUDED_IMFNAMESPACE_H
36#define INCLUDED_IMFNAMESPACE_H
37
38//
39// The purpose of this file is to have all of the Imath symbols defined within
40// the OPENEXR_IMF_INTERNAL_NAMESPACE namespace rather than the standard Imath
41// namespace. Those symbols are made available to client code through the
42// OPENEXR_IMF_NAMESPACE in addition to the OPENEXR_IMF_INTERNAL_NAMESPACE.
43//
44// To ensure source code compatibility, the OPENEXR_IMF_NAMESPACE defaults to
45// Imath and then "using namespace OPENEXR_IMF_INTERNAL_NAMESPACE;" brings all
46// of the declarations from the OPENEXR_IMF_INTERNAL_NAMESPACE into the
47// OPENEXR_IMF_NAMESPACE.
48// This means that client code can continue to use syntax like
49// Imf::Header, but at link time it will resolve to a
50// mangled symbol based on the OPENEXR_IMF_INTERNAL_NAMESPACE.
51//
52// As an example, if one needed to build against a newer version of Imath and
53// have it run alongside an older version in the same application, it is now
54// possible to use an internal namespace to prevent collisions between the
55// older versions of Imath symbols and the newer ones. To do this, the
56// following could be defined at build time:
57//
58// OPENEXR_IMF_INTERNAL_NAMESPACE = Imf_v2
59//
60// This means that declarations inside Imath headers look like this (after
61// the preprocessor has done its work):
62//
63// namespace Imf_v2 {
64// ...
65// class declarations
66// ...
67// }
68//
69// namespace Imf {
70// using namespace IMF_NAMESPACE_v2;
71// }
72//
73
74//
75// Open Source version of this file pulls in the OpenEXRConfig.h file
76// for the configure time options.
77//
78#include "OpenEXRConfig.h"
79
80
81#ifndef OPENEXR_IMF_NAMESPACE
82#define OPENEXR_IMF_NAMESPACE Imf
83#endif
84
85#ifndef OPENEXR_IMF_INTERNAL_NAMESPACE
86#define OPENEXR_IMF_INTERNAL_NAMESPACE OPENEXR_IMF_NAMESPACE
87#endif
88
89//
90// We need to be sure that we import the internal namespace into the public one.
91// To do this, we use the small bit of code below which initially defines
92// OPENEXR_IMF_INTERNAL_NAMESPACE (so it can be referenced) and then defines
93// OPENEXR_IMF_NAMESPACE and pulls the internal symbols into the public
94// namespace.
95//
96
97namespace OPENEXR_IMF_INTERNAL_NAMESPACE {}
98namespace OPENEXR_IMF_NAMESPACE {
99 using namespace OPENEXR_IMF_INTERNAL_NAMESPACE;
100}
101
102//
103// There are identical pairs of HEADER/SOURCE ENTER/EXIT macros so that
104// future extension to the namespace mechanism is possible without changing
105// project source code.
106//
107
108#define OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_ENTER namespace OPENEXR_IMF_INTERNAL_NAMESPACE {
109#define OPENEXR_IMF_INTERNAL_NAMESPACE_HEADER_EXIT }
110
111#define OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_ENTER namespace OPENEXR_IMF_INTERNAL_NAMESPACE {
112#define OPENEXR_IMF_INTERNAL_NAMESPACE_SOURCE_EXIT }
113
114
115#endif /* INCLUDED_IMFNAMESPACE_H */
116

source code of include/OpenEXR/ImfNamespace.h