Using a STL map of function pointers
In C++11 you can do something like this : This Interface needs only the return type and it takes care of everything else from the caller side.
#include <string>
#include <iostream>
#include <map>
#include <vector>
#include <typeinfo>
#include <typeindex>
#include <cassert>
void fun1(void){
std::cout<<"inside fun1\n";
}
int fun2(){
std::cout<<"inside fun2\n";
return 2;
}
int fun3(int a){
std::cout<<"inside fun3\n";
return a;
}
std::vector<int> fun4(){
std::cout<<"inside fun4\n";
std::vector<int> v(4,100);
return v;
}
// every function pointer will be stored as this type
typedef void (*voidFunctionType)(void);
struct Interface{
std::map<std::string,std::pair<voidFunctionType,std::type_index>> m1;
template<typename T>
void insert(std::string s1, T f1){
auto tt = std::type_index(typeid(f1));
m1.insert(std::make_pair(s1,
std::make_pair((voidFunctionType)f1,tt)));
}
template<typename T,typename... Args>
T searchAndCall(std::string s1, Args&&... args){
auto mapIter = m1.find(s1);
/*chk if not end*/
auto mapVal = mapIter->second;
// auto typeCastedFun = reinterpret_cast<T(*)(Args ...)>(mapVal.first);
auto typeCastedFun = (T(*)(Args ...))(mapVal.first);
//compare the types is equal or not
assert(mapVal.second == std::type_index(typeid(typeCastedFun)));
return typeCastedFun(std::forward<Args>(args)...);
}
};
int main(){
Interface a1;
a1.insert("fun1",fun1);
a1.insert("fun2",fun2);
a1.insert("fun3",fun3);
a1.insert("fun4",fun4);
a1.searchAndCall<void>("fun1");
int retVal = a1.searchAndCall<int>("fun3",2);
a1.searchAndCall<int>("fun2");
auto temp = a1.searchAndCall<std::vector<int>>("fun4");
return 0;
}
Whatever your function signatures are:
typedef void (*ScriptFunction)(void); // function pointer type
typedef std::unordered_map<std::string, ScriptFunction> script_map;
// ...
void some_function()
{
}
// ...
script_map m;
m.emplace("blah", &some_function);
// ...
void call_script(const std::string& pFunction)
{
auto iter = m.find(pFunction);
if (iter == m.end())
{
// not found
}
(*iter->second)();
}
Note that the ScriptFunction
type could be generalized to std::function</* whatever*/>
so you can support any callable thing, not just exactly function pointers.