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#include <iostream>
using namespace std;
 
class FeaturesExample {};
class Example : public FeaturesExample {};
 
class Base {
 public:
  float getFloat(const FeaturesExample& ex) const {
  	return (this->*getFloatImplPtr_)(ex);
  }
  float (Base::*getFloatImplPtr_)(const FeaturesExample& ex) const;
  float getFloatImpl_(const FeaturesExample& ex) const {
  	return 0.0;
  }
};
class Derived : public Base {
 public:
  float getFloatImpl(const Example& ex) {
  	return 1.0;
  }
};
int main() {
	FeaturesExample ex;
	Derived derived;
	derived.getFloatImplPtr_ = (decltype(derived.getFloatImplPtr_))(&Derived::getFloatImpl);
	derived.getFloat();
	return 0;
}

prog.cpp: In function ‘int main()’:
prog.cpp:27:19: error: no matching function for call to ‘Derived::getFloat()’
  derived.getFloat();
                   ^
prog.cpp:9:9: note: candidate: float Base::getFloat(const FeaturesExample&) const
   float getFloat(const FeaturesExample& ex) const {
         ^~~~~~~~
prog.cpp:9:9: note:   candidate expects 1 argument, 0 provided

Standard output is empty