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#include <algorithm>
#include <functional>
#include <iostream>
#include <iterator>
#include <list>
#include <set>
#include <vector>
 
template<typename ContainerOut, typename X, typename Y, typename ContainerIn>
ContainerOut Map( const ContainerIn& xs, const std::function<Y( const X& )>& f )
{
	ContainerOut ys;
	std::transform( begin( xs ), end( xs ), std::inserter( ys, end( ys ) ), f );
	return ys;
}
 
struct Foo {
	Foo( int val ) : val_( val ) {}
	int val_;
};
 
std::set<int> FooValsToIntSet( const std::list<Foo>& foos )
{
	//Map<std::set<int>, Foo, int>
	return Map( foos, []( const Foo& foo )
	{
		return foo.val_;
	} );
}
 
int main()
{
	std::list<Foo> foos = { 1, 2, 2, 3 };
	std::set<int> vals = FooValsToIntSet( foos );
	for ( auto& v : vals )
		std::cout << v << std::endl;
}

prog.cpp: In function 'std::set<int> FooValsToIntSet(const std::list<Foo>&)':
prog.cpp:28:4: error: no matching function for call to 'Map(const std::list<Foo>&, FooValsToIntSet(const std::list<Foo>&)::<lambda(const Foo&)>)'
  } );
    ^
prog.cpp:10:14: note: candidate: template<class ContainerOut, class X, class Y, class ContainerIn> ContainerOut Map(const ContainerIn&, const std::function<Y(const X&)>&)
 ContainerOut Map( const ContainerIn& xs, const std::function<Y( const X& )>& f )
              ^
prog.cpp:10:14: note:   template argument deduction/substitution failed:
prog.cpp:28:4: note:   'FooValsToIntSet(const std::list<Foo>&)::<lambda(const Foo&)>' is not derived from 'const std::function<Y(const X&)>'
  } );
    ^

Standard output is empty