How to handle a large number of 'using' statements?

Question

Is there an etiquette for dealing with a large number of using statements in C++? For example if I have a header file with the following:

using std::vector;
using std::string;
...
using std::map;
...

where ... indicate further extensions of using statement. I would like a way to reduce 'clutter'. Or is it just bad practice to have a large number of using statements?

Answer 1

One way to handle them is to not use them in namespace scope. You can use qualified names like this for example:

std::vector an_example {1, 2, 3};