[C++ korea] effective modern c++ study item 3 understand decltype +이세현

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decltype(i)는 const intdecltype(i)는 const intdecltype(f) is bool(const Widget&)

decltype(Point::x) is intdecltype(f(w)) is bool

decltype(v) is vector<int>decltype(v[0]) is int&

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Effective Modern C++ StudyC++ Korea

myWidget1의 type은WidgetmyWidget2이 type은 const Widget&

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c++14 version c++11 version

std::forward템플릿으로사용할시우측값매개변수에좌측값인수를넣을수 있다.원래좌측값인것은좌측값으로, 원래우측값인것은우측값으로캐스팅해주는역활

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decltype(x)는 int -> f1은 int를 반환

decltype((x))는 int& -> f2은 int&를 반환지역변수의참조를반환하는것은미정의동작! (절대로하지 말라는얘기)

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