How to declare a static const char* in your header file?

Question

I\'d like to define a constant char* in my header file for my .cpp file to use. So I\'ve tried this:

private:
    static const char *SOMETHING = \"sommething\";         


        

Answer 1

There is a trick you can use with templates to provide H file only constants.

(note, this is an ugly example, but works verbatim in at least in g++ 4.6.1.)

(values.hpp file)

#include 

template
class tValues
{
public:
   static const char* myValue;
};

template  const char* tValues::myValue = "This is a value";

typedef tValues<0> Values;

std::string otherCompUnit(); // test from other compilation unit

(main.cpp)

#include 
#include "values.hpp"

int main()
{
   std::cout << "from main: " << Values::myValue << std::endl;
   std::cout << "from other: " << otherCompUnit() << std::endl;
}

(other.cpp)

#include "values.hpp"

std::string otherCompUnit () {
   return std::string(Values::myValue);
}

Compile (e.g. g++ -o main main.cpp other.cpp && ./main) and see two compilation units referencing the same constant declared in a header:

from main: This is a value
from other: This is a value

---

In MSVC, you may instead be able to use __declspec(selectany)

For example:

__declspec(selectany) const char* data = "My data";