fork download
copy 
  1. #include <iostream>
  2. #include <typeinfo>
  3. #include <cxxabi.h>
  4. #include <memory>
  5.  
  6. template <class T>
  7. std::string GetTypeName()
  8. {
  9.   //http://stackoverflow.com/questions/23266391/find-out-the-type-of-auto/23266701#23266701
  10.   std::unique_ptr<char, void(*)(void*)> name{abi::__cxa_demangle(typeid(T).name(), 0, 0, nullptr), std::free};
  11.   return name.get();
  12. }
  13.  
  14.  
  15. struct A
  16. {
  17.   struct AA {};
  18.   struct AB {};
  19.   struct AC {};
  20.  
  21.   struct BA {};
  22.   struct BB {};
  23.   struct BC {};
  24.  
  25.   BA GetBTypeFromAType(AA a) { return BA(); }
  26.   BB GetBTypeFromAType(AB a) { return BB(); }
  27.   BC GetBTypeFromAType(AC a) { return BC(); }
  28.  
  29.   template <typename AType>
  30.   void Func(AType a)
  31.   {
  32.     //using BType = typename std::result_of<decltype(GetBTypeFromAType(a))>::type;
  33.     std::cout << "Func called with " << GetTypeName<AType>() << " and got " << GetTypeName<decltype(GetBTypeFromAType(a))>() << std::endl;
  34.   }
  35. };
  36.  
  37. int main()
  38. {
  39.   A a;
  40.   A::AA aa;
  41.   A::AB ab;
  42.   A::AC ac;
  43.   a.Func(aa);
  44.   a.Func(ab);
  45.   a.Func(ac);
  46.   return 0;
  47. }
Success #stdin #stdout 0s 4516KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Func called with A::AA and got A::BA
Func called with A::AB and got A::BB
Func called with A::AC and got A::BC
https://ideone.com/yLpf7E
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!