Defining a scope with a pre-created namespace (C ++)

Question

To avoid selecting everything from the STL, you can enter

using namespace std; 

To avoid defining just a few things, you can enter:

 using std::cout; using std::cin; 

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I want to write a library that acts the same way. However, instead of including specific classes, I want to be able to include specific collections of functions.

So, for example, I have the code:

• String Functions Collection
• Set of math functions

They are part of the same namespace, but I can include the pieces I want

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This is sudo-ish code, but I think it gives my idea:

 namespace Everything{ namespace StringFunctions{ void str1(string & str); void str2(string & str); void str3(string & str); void str4(string & str); void str5(string & str); } namespace MathFunctions { void math1(int & num); void math2(int & num); void math3(int & num); void math4(int & num); void math5(int & num); } } 

then I want to be able to do something like:

 #include "Everything.h" using Everything::Stringfunctions; int main(){ str1("string"); //this works, I can call this! math1(111); //compile error: I've never heard of that function! return 0; } 

Obviously this does not work, and I'm a little confused about how to split my library. I don’t want to create classes and then use the “dot operator” everywhere, but I also don’t want to include a ton of header files.

Maybe I'm wrong about that. I hope everyone can help me take the right approach here.

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EDIT:

It works by writing:

 using namespace Everything::Stringfunctions; 

This is very obvious now in retrospect.

Answer 1

The way you wrote your library in the example you gave is sufficient.

People can get each function from the Everything::Stringfunctions using namespace Everything::Stringfunctions .

Answer 2

You should consider splitting functions into different headers regardless of whether you end up compiling nightmares. However, I think using namespace Everything::Stringfunctions; should do it (with the addition of namespace there. I haven't even tried to compile).

Answer 3

It seems that you want to work if you are using namespace , not just using . See here (the program compiles and displays "5").