Can a string be converted to a type in C++?

Question

OOP

There is a parent class function

class function
{
public:
function (const string &Name) name(Name) {}
virtual double get_out (const double x) const =0;
string name;
};

And there are a bunch of classes that inherit this class by overriding the get_out method
for example:

class sinus : public function
{
sinus () :  function("sinus")
double get_out (const double x) { return sin(x);}
}

Next, I need to create a function, depending on the name of the function
. For each function, the name matches the name of the class.

function * get_function (const string name)
{
if (name == "sinus")
    retrun new sinus();
}

Is there a way to somehow avoid the huge iff stack? In order not to create your own if for each function, but to convert the string "sinus" to the sinus type?

Answer 1

There is no such way in C++. But you can create a string map for function factories, register all functions in it, and get it by name.

Answer 2

template <class _T>
class FunctionT : public function
{
public:
    static const char m_name[];
    function* get_function(const string& name) {
        if (name == m_name)
            return new _T;
        return nullptr;
    }
};

using namespace std;

vector<function*> functions;
functions.push_back( new FunctionT<sinus> );
functions.push_back( new FunctionT<cosinus> );
functions.push_back( new Function<tangens> );

for(vector<function*>::iterator it = functions.begin(); it != functions.end(); ++it) {
    function* f = (*it)->get_function("sinus");
    if ( f != nullptr )
          f->get_out();
}