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| − | {{title|C++ keywords}}
| + | [[File:https://pbs.twimg.com/media/EGYkQtYWsAItEJp.jpg]] |
| − | {{cpp/keyword/navbar}}
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| − | This is a list of reserved keywords in C++. Since they are used by the language, these keywords are not available for re-definition or overloading.
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| − | {|class="wikitable"
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| − | |-
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| − | ! A – C !! D – P !! R – Z
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| − | |- style="vertical-align:top;"
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| − | {{rlt|alignas}} {{mark c++11}}<br>
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| − | {{rlt|alignof}} {{mark c++11}}<br>
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| − | {{rlt|and}}<br>
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| − | {{rlt|and_eq}}<br>
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| − | {{rlt|asm}}<br>
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| − | {{ltt|cpp/language/transactional memory|atomic_cancel}} {{mark since tm ts}}<br>
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| − | {{ltt|cpp/language/transactional memory|atomic_commit}} {{mark since tm ts}}<br>
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| − | {{ltt|cpp/language/transactional memory|atomic_noexcept}} {{mark since tm ts}}<br>
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| − | {{rlt|auto}} {{mark|1}}<br>
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| − | {{rlt|bitand}}<br>
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| − | {{rlt|bitor}}<br>
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| − | {{rlt|bool}}<br>
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| − | {{rlt|break}}<br>
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| − | {{rlt|case}}<br>
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| − | {{rlt|catch}}<br>
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| − | {{rlt|char}}<br>
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| − | {{rlt|char8_t}} {{mark c++20}}<br>
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| − | {{rlt|char16_t}} {{mark c++11}}<br>
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| − | {{rlt|char32_t}} {{mark c++11}}<br>
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| − | {{rlt|class}} {{mark|1}}<br>
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| − | {{rlt|compl}}<br>
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| − | {{rlt|concept}} {{mark c++20}}<br>
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| − | {{rlt|const}}<br>
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| − | {{rlt|consteval}} {{mark c++20}}<br>
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| − | {{rlt|constexpr}} {{mark c++11}}<br>
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| − | {{rlt|constinit}} {{mark c++20}}<br>
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| − | {{rlt|const_cast}}<br>
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| − | {{rlt|continue}}<br>
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| − | {{rlt|co_await}} {{mark c++20}}<br>
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| − | {{rlt|co_return}} {{mark c++20}}<br>
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| − | {{rlt|co_yield}} {{mark c++20}}<br>
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| − | {{rlt|decltype}} {{mark c++11}}<br>
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| − | {{rlt|default}} {{mark|1}}<br>
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| − | {{rlt|delete}} {{mark|1}}<br>
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| − | {{rlt|do}}<br>
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| − | {{rlt|double}}<br>
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| − | {{rlt|dynamic_cast}}<br>
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| − | {{rlt|else}}<br>
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| − | {{rlt|enum}}<br>
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| − | {{rlt|explicit}}<br>
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| − | {{rlt|export}} {{mark|1}} {{mark|3}}<br>
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| − | {{rlt|extern}} {{mark|1}}<br>
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| − | {{rlt|false}}<br>
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| − | {{rlt|float}}<br>
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| − | {{rlt|for}}<br>
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| − | {{rlt|friend}}<br>
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| − | {{rlt|goto}}<br>
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| − | {{rlt|if}}<br>
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| − | {{rlt|inline}} {{mark|1}}<br>
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| − | {{rlt|int}}<br>
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| − | {{rlt|long}}<br>
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| − | {{rlt|mutable}} {{mark|1}}<br>
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| − | {{rlt|namespace}}<br>
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| − | {{rlt|new}}<br>
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| − | {{rlt|noexcept}} {{mark c++11}}<br>
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| − | {{rlt|not}}<br>
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| − | {{rlt|not_eq}}<br>
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| − | {{rlt|nullptr}} {{mark c++11}}<br>
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| − | {{rlt|operator}}<br>
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| − | {{rlt|or}}<br>
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| − | {{rlt|or_eq}}<br>
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| − | {{rlt|private}}<br>
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| − | {{rlt|protected}}<br>
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| − | {{rlt|public}}<br>
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| − | {{rlt|reflexpr}} {{mark since reflection ts}}<br>
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| − | {{rlt|register}} {{mark|2}}<br>
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| − | {{rlt|reinterpret_cast}}<br>
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| − | {{rlt|requires}} {{mark c++20}}<br>
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| − | {{rlt|return}}<br>
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| − | {{rlt|short}}<br>
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| − | {{rlt|signed}}<br>
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| − | {{rlt|sizeof}} {{mark|1}}<br>
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| − | {{rlt|static}}<br>
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| − | {{rlt|static_assert}} {{mark c++11}}<br>
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| − | {{rlt|static_cast}}<br>
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| − | {{rlt|struct}} {{mark|1}}<br>
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| − | {{rlt|switch}}<br>
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| − | {{ltt|cpp/language/transactional memory|synchronized}} {{mark since tm ts}}<br>
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| − | {{rlt|template}}<br>
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| − | {{rlt|this}} {{mark|4}}<br>
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| − | {{rlt|thread_local}} {{mark c++11}}<br>
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| − | {{rlt|throw}}<br>
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| − | {{rlt|true}}<br>
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| − | {{rlt|try}}<br>
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| − | {{rlt|typedef}}<br>
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| − | {{rlt|typeid}}<br>
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| − | {{rlt|typename}}<br>
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| − | {{rlt|union}}<br>
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| − | {{rlt|unsigned}}<br>
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| − | {{rlt|using}} {{mark|1}}<br>
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| − | {{rlt|virtual}}<br>
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| − | {{rlt|void}}<br>
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| − | {{rlt|volatile}}<br>
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| − | {{rlt|wchar_t}}<br>
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| − | {{rlt|while}}<br>
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| − | {{rlt|xor}}<br>
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| − | {{rlt|xor_eq}}
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| − | |}
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| − | * {{mark|1}} — meaning changed or new meaning added in C++11.
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| − | * {{mark|2}} — meaning changed in C++17.
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| − | * {{mark|3}} — meaning changed in C++20.
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| − | * {{mark|4}} — new meaning added in C++23.
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| − | Note that {{rlt|and}}, {{rlt|bitor}}, {{rlt|or}}, {{rlt|xor}}, {{rlt|compl}}, {{rlt|bitand}}, {{rlt|and_eq}}, {{rlt|or_eq}}, {{rlt|xor_eq}}, {{rlt|not}}, and {{rlt|not_eq}} (along with the digraphs {{c|<%}}, {{c|%>}}, {{c|<:}}, {{c|:>}}, {{c|%:}}, and {{c|%:%:}}) provide an [[cpp/language/operator alternative|alternative way to represent standard tokens]].
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| − | In addition to keywords, there are ''identifiers with special meaning'', which may be used as names of objects or functions, but have special meaning in certain contexts.
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| − | {|class="wikitable"
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| − | |-
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| − | {{ltt|cpp/language/final}} {{mark c++11}}<br>
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| − | {{ltt|cpp/language/override}} {{mark c++11}}<br>
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| − | {{ltt|cpp/language/transactional memory|transaction_safe}} {{mark since tm ts}}<br>
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| − | {{ltt|cpp/language/transactional memory|transaction_safe_dynamic}} {{mark since tm ts}}<br>
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| − | {{rlt|import}} {{mark c++20}}<br>
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| − | {{rlt|module}} {{mark c++20}}
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| − | |}
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| − | Also, all {{lt|cpp/language/identifiers}} that contain a double underscore {{tt|__}} in any position and each identifier that begins with an underscore followed by an uppercase letter is always reserved and all identifiers that begin with an underscore are reserved for use as names in the global namespace. See {{lt|cpp/language/identifiers}} for more details.
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| − | The namespace {{tt|std}} is used to place names of the standard C++ library. See [[cpp/language/extending std|Extending namespace std]] for the rules about adding names to it.
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| − | {{rrev|since=c++11|The name {{tt|posix}} is reserved for a future top-level namespace. The behavior is undefined if a program declares or defines anything in that namespace.}}
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| − | The following tokens are recognized by the {{rlp|preprocessor}} when in context of a preprocessor directive:
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| − | {|class="wikitable"
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| − | |-
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| − | {{ltt|cpp/preprocessor/conditional|if}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|elif}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|else}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|endif}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|ifdef}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|ifndef}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|elifdef}} {{mark c++23}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|elifndef}} {{mark c++23}}<br>
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| − | {{ltt|cpp/preprocessor/replace|define}}<br>
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| − | {{ltt|cpp/preprocessor/replace|undef}}<br>
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| − | {{ltt|cpp/preprocessor/include|include}}<br>
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| − | {{ltt|cpp/preprocessor/line|line}}<br>
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| − | {{ltt|cpp/preprocessor/error|error}}<br>
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| − | {{ltt|cpp/preprocessor/error|warning}} {{mark c++23}}<br>
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| − | {{ltt|cpp/preprocessor/impl|pragma}}<br>
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| − | {{ltt|cpp/preprocessor/conditional|defined}}<br>
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| − | {{ltt|cpp/feature test|__has_include}} {{mark c++17}}<br>
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| − | {{ltt|cpp/feature test|__has_cpp_attribute}} {{mark c++20}}
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| − | {{rlt|export}} {{mark c++20}}<br>
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| − | {{rlt|import}} {{mark c++20}}<br>
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| − | {{rlt|module}} {{mark c++20}}
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| − | |}
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| − | The following tokens are recognized by the {{rlp|preprocessor}} ''outside'' the context of a preprocessor directive:
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| − | {|class="wikitable"
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| − | |-
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| − | {{ltt|cpp/preprocessor/impl|_Pragma}} {{mark c++11}}
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| − | |}
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| − | ===See also===
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| − | {{dsc begin}}
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| − | {{dsc see c|c/keyword|C keywords|nomono=true}}
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| − | {{dsc end}}
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| − | {{langlinks|ar|de|es|fr|it|ja|ko|pl|pt|ru|zh}}
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