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#include <map>
#include <cstdio>
 
class NotCopyable
    {
	public:
		NotCopyable(char key):m_x(key){}
		NotCopyable(NotCopyable&& a)
			{
			printf("create %p from %p\n",this,&a);
			m_x=a.m_x;
			}
 
		NotCopyable& operator=(NotCopyable&& a)
			{
			printf("move %p into %p\n",&a,this);
			return *this;
			}
		bool operator<(const NotCopyable& nc) const
			{return m_x<nc.m_x;}
		char m_x;
	};
 
int main()
	{
	std::map<NotCopyable,int> my_map;
	my_map.insert(std::pair<NotCopyable,int>('A',1));
	my_map.insert(std::pair<NotCopyable,int>('B',2));
	my_map.insert(std::pair<NotCopyable,int>('C',3));
 
	auto i=my_map.begin();
	while(i!=my_map.end())
		{
		printf("'%c' =>  %d\n",i->first.m_x,i->second);
		NotCopyable foo=std::move( i->first ); 
		++i;
		}
 
	return 0;
	}
 

prog.cpp: In function ‘int main()’:
prog.cpp:35:39: error: use of deleted function ‘constexpr NotCopyable::NotCopyable(const NotCopyable&)’
   NotCopyable foo=std::move( i->first ); 
                                       ^
prog.cpp:4:7: note: ‘constexpr NotCopyable::NotCopyable(const NotCopyable&)’ is implicitly declared as deleted because ‘NotCopyable’ declares a move constructor or move assignment operator
 class NotCopyable
       ^

Standard output is empty