WebFeb 15, 2024 · The answer is big NO. What really!! The std namespace is special, The built in C++ library routines are kept in the standard namespace. That includes stuff like cout, cin, string, vector, map, etc ... WebSep 20, 2013 · When you make a call to using namespace ; all symbols in that namespace will become visible without adding the namespace prefix. A symbol may be for instance a function, class or a variable. E.g. if you add using namespace std; you can write just cout instead of std::cout when calling the operator …
c++ - What does "using namespace" do exactly? - Stack Overflow
WebDec 7, 2015 · No need to look it up anywhere. namespace X { struct C { static std::string test; }; } using namespace X; std::string C::test = "Test"; In this code, the compiler needs to know what C is to make sense of the definition of C::test. It therefore does a name lookup of C, which indeed finds X::C thanks to the using directive. WebAug 3, 2024 · using namespace std; c++ 공부를 시작하면 가장 먼저 알아야 하는 것! 왜 이 코드 "using namespace std; " 를 먼저 넣어두고 실행해야 하는지 아래 예제를 통해 확인해본다. algorithm 안에 있는 max 함수를 사용하고자 한다. include를 통해 아래와 같이 코드를 작성했는데 컴파일 에러가 발생한다. #include int main() { int n ... led light bulbs winter
C++ Standard Library - cppreference.com
WebDepende de lo que quieras hacer y el tamaño del problema que estés resolviendo.. Si utilizas mucho la STL (librería estándar de C++), que es en muchos casos es una buena idea porque está bastante bien hecha, es bastante cómodo poner using namespace std; al principio y olvidarte de poner std::vector cada vez que quieras declarar un … WebNov 6, 2008 · using namespace std 意思:. using 和namespace都是C++的关键词。. std 是标准程序库所驻之命名空间(namespace)的名称。. 如果使用Boost的库 ,那就写 using namespace boost; 如果使用C++ 标准库 那就写 using namespace std; 就是暴露std这个名字空间,你就可以调用std这个名字空间下的 ... WebSep 21, 2009 · The problem with putting using namespace in the header files of your classes is that it forces anyone who wants to use your classes (by including your header files) to also be 'using' (i.e. seeing everything in) those other namespaces. However, you may feel free to put a using statement in your (private) *.cpp files. how to enable bing chat