I have heard using namespace std; is wrong, and that I should use std::cout and std::cin directly instead. Why is this? Does it risk declaring variables that share the same name as something in the...

The name vector exists within namespace std (as a templated class). In main() when it sees usage of the name vector, the previous using namespace std causes the compiler to look in std for names that …

There seem to be different views on using 'using' with respect to the std namespace. Some say use ' using namespace std', other say don't but rather prefix std functions that are to be used with '...

Sep 20, 2013 · E.g. if you add using namespace std; you can write just cout instead of std::cout when calling the operator cout defined in the namespace std. This is somewhat dangerous because …

Sep 3, 2008 · But now I'm working in C++. How do you use namespaces in C++? Do you create a single namespace for the entire application, or do you create namespaces for the major components? If so, …

Oct 13, 2015 · When you type using namespace std, you are taking everything inside of the namespace std and moving it to the global scope, so that you can use the shorter cout instead of the more fully …

Jan 19, 2016 · Неожиданный using namespace std, привнесённый в код заголовочным файлом, может всё поломать. Однако в cpp-файлах я всё время использую using namespace std. И …

May 23, 2019 · The using namespace std; directive just says "For anything in the std namespace that I know about, you can leave off the std:: prefix". But without the #include <vector> (directly or indirectly …

May 31, 2012 · This question may be a duplicate, but I can't find a good answer. Short and simple, what requires me to declare using namespace std; in C++ programs?

Dec 16, 2021 · It's equivalent to using namespace ::std; and also equivalent to using namespace std;. The :: refers to the global namespace, and std is put in the global namespace indeed.