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190+ 最終更新日時(UTC):
191+ < span itemprop ="datePublished " content ="2024-11-11T08:15:48 ">
192+ 2024年11月11日 08時15分48秒
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195+ < span itemprop ="author " itemscope itemtype ="http://schema.org/Person ">
196+ < span itemprop ="name "> Akira Takahashi</ span >
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198+ が更新
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215+ < h1 itemprop ="name "> < span class ="token "> 列挙値から算術型への暗黙変換を非推奨化 [P1120R0]</ span > < span class ="cpp cpp20 " title ="C++20で追加 "> (C++20)</ span > </ h1 >
216+ < div itemprop ="articleBody "> < p > </ p >
217+ < p > このページはC++20に採用された言語機能の変更を解説しています。</ p >
218+ < p > のちのC++規格でさらに変更される場合があるため< a href ="#relative-page "> 関連項目</ a > を参照してください。</ p >
219+ < p > </ p >
220+ < h2 > 概要</ h2 >
221+ < p > < a href ="consistent_comparison.html "> 三方比較演算子</ a > の導入にともない、一方のオペランドが列挙型である場合の算術演算での暗黙の算術変換を非推奨とする。</ p >
222+ < p > < div class ="codehilite "> < pre > < span > </ span > < code > < span class ="k "> enum</ span > < span class ="n "> E1</ span > < span class ="p "> {</ span > < span class ="n "> e</ span > < span class ="p "> };</ span >
223+ < span class ="k "> enum</ span > < span class ="n "> E2</ span > < span class ="p "> {</ span > < span class ="n "> f</ span > < span class ="p "> };</ span >
224+
225+ < span class ="kt "> bool</ span > < span class ="n "> b</ span > < span class ="o "> =</ span > < span class ="n "> e</ span > < span class ="o "> <=</ span > < span class ="mf "> 3.7</ span > < span class ="p "> ;</ span > < span class ="c1 "> // C++20から非推奨</ span >
226+ < span class ="kt "> int</ span > < span class ="n "> k</ span > < span class ="o "> =</ span > < span class ="n "> f</ span > < span class ="o "> -</ span > < span class ="n "> e</ span > < span class ="p "> ;</ span > < span class ="c1 "> // C++20から非推奨</ span >
227+ < span class ="kt "> int</ span > < span class ="n "> x</ span > < span class ="o "> =</ span > < span class ="o "> +</ span > < span class ="n "> f</ span > < span class ="o "> -</ span > < span class ="n "> e</ span > < span class ="p "> ;</ span > < span class ="c1 "> // OK</ span >
228+ </ code > </ pre > </ div >
229+ </ p >
230+ < h2 > 関連項目</ h2 >
231+ < ul >
232+ < li > < a href ="consistent_comparison.html "> C++20 < code > <=></ code > /< code > ==</ code > による比較演算子の自動定義</ a > </ li >
233+ < li > < a href ="../cpp26/remove_deprecated_arithmetic_conversion_on_enumerations.html "> C++26 非推奨となっていた列挙型の算術変換を削除</ a > </ li >
234+ </ ul >
235+ < h2 > 参照</ h2 >
236+ < ul >
237+ < li > < a href ="https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1120r0.html " target ="_blank "> P1120R0 Consistency improvements for < code > <=></ code > and other comparison operators</ a > </ li >
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