class Test
{
public:
SOMETHING DoIt(int a)
{
float FLOAT = 1.2;
int INT = 2;
char CHAR = 'a';
switch(a)
{
case 1: return INT;
case 2: return FLOAT;
case 3: return CHAR;
}
}
};
int main(int argc, char* argv[])
{
Test obj;
cout<<obj.DoIt(1);
return 0;
}
Now, using the knowledge that a = 1 implies that I need to return an integer, etc., is there anyway Doit() can return a variable of variable data type?
Essentially, with what do I replace SOMETHING ?
PS: I'm trying to find a an alternative to returning a structure/union containing these data types.
You can use boost::any or boost::variant to do what you want. I recommend boost::variant because you know the collection of types you want to return.
This is a very simple example, though you can do much more with variant. Check the reference for more examples :)
#include "boost/variant.hpp"
#include <iostream>
typedef boost::variant<char, int, double> myvariant;
myvariant fun(int value)
{
if(value == 0)
{
return 1001;
}
else if(value == 1)
{
return 3.2;
}
return 'V';
}
int main()
{
myvariant v = fun(0);
std::cout << v << std::endl;
v = fun(1);
std::cout << v << std::endl;
v = fun(54151);
std::cout << v << std::endl;
}
The output:
1001
3.2
V
I would use boost::variant instead of a union because you can't use non-POD types inside union. Also, boost::any is great if you don't know the type you are dealing with. Otherwise, I would use boost::variant because it is much more efficient and safer.
Answering the edited question: If you don't want to ship Boost with your code, take a look at bcp. The description of bcp from the same link:
The bcp utility is a tool for extracting subsets of Boost, it's useful for Boost authors who want to distribute their library separately from Boost, and for Boost users who want to distribute a subset of Boost with their application.
bcp can also report on which parts of Boost your code is dependent on, and what licences are used by those dependencies.