1 | // scoped_enum_emulation.hpp ---------------------------------------------------------// |
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2 | |
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3 | // Copyright Beman Dawes, 2009 |
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4 | |
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5 | // Distributed under the Boost Software License, Version 1.0. |
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6 | // See http://www.boost.org/LICENSE_1_0.txt |
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7 | |
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8 | // Generates C++0x scoped enums if the feature is present, otherwise emulates C++0x |
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9 | // scoped enums with C++03 namespaces and enums. The Boost.Config BOOST_NO_SCOPED_ENUMS |
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10 | // macro is used to detect feature support. |
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11 | // |
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12 | // See http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2347.pdf for a |
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13 | // description of the scoped enum feature. Note that the committee changed the name |
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14 | // from strongly typed enum to scoped enum. |
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15 | // |
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16 | // Caution: only the syntax is emulated; the semantics are not emulated and |
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17 | // the syntax emulation doesn't include being able to specify the underlying |
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18 | // representation type. |
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19 | // |
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20 | // The emulation is via struct rather than namespace to allow use within classes. |
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21 | // Thanks to Andrey Semashev for pointing that out. |
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22 | // |
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23 | // Helpful comments and suggestions were also made by Kjell Elster, Phil Endecott, |
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24 | // Joel Falcou, Mathias Gaunard, Felipe Magno de Almeida, Matt Calabrese, Vincente |
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25 | // Botet, and Daniel James. |
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26 | // |
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27 | // Sample usage: |
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28 | // |
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29 | // BOOST_SCOPED_ENUM_START(algae) { green, red, cyan }; BOOST_SCOPED_ENUM_END |
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30 | // ... |
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31 | // BOOST_SCOPED_ENUM(algae) sample( algae::red ); |
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32 | // void foo( BOOST_SCOPED_ENUM(algae) color ); |
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33 | // ... |
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34 | // sample = algae::green; |
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35 | // foo( algae::cyan ); |
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36 | |
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37 | #ifndef BOOST_SCOPED_ENUM_EMULATION_HPP |
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38 | #define BOOST_SCOPED_ENUM_EMULATION_HPP |
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39 | |
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40 | #include <boost/config.hpp> |
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41 | |
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42 | #ifdef BOOST_NO_SCOPED_ENUMS |
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43 | |
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44 | # define BOOST_SCOPED_ENUM_START(name) struct name { enum enum_type |
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45 | # define BOOST_SCOPED_ENUM_END }; |
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46 | # define BOOST_SCOPED_ENUM(name) name::enum_type |
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47 | |
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48 | #else |
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49 | |
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50 | # define BOOST_SCOPED_ENUM_START(name) enum class name |
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51 | # define BOOST_SCOPED_ENUM_END |
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52 | # define BOOST_SCOPED_ENUM(name) name |
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53 | |
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54 | #endif |
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55 | |
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56 | #endif // BOOST_SCOPED_ENUM_EMULATION_HPP |
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