inserting object in a map without copying the object - c++

Question

Is it possible to insert objects in a map, if the class of the object has disabled copy constructor and disabled copy operator? Is move semantics useful here?
#include <map>
class T {
public:
T(int v): x(v) {};
private:
T(const T &other); // disabled!
T &operator=(const T &other); // disabled!
int x;
};
int main() {
std::map<int, T> m;
m[42] = T(24); // compilation error here!
}
edit I was not completely clear. The object is huge, so I don't want to make unnecessary copies of it. But I can modify the code of the class (maybe I need to implement move semantics?) and not the user code (the main function in the example).

Answer 1

Use emplacement syntax:
m.emplace(std::piecewise_construct,
std::forward_as_tuple(42), std::forward_as_tuple(24));
// ^^ ^^
// int(42) T(24)
Or, in C++17, use try_emplace:
m.try_emplace(42, 24);

Answer 2

This might be what you are looking for:
class T {
public:
T(){};
T(int v): x(v) {};
T(const T &other) = delete;
T(T&& other) {x = other.x; std::cout << "move ctor\n";}
T &operator=(const T &other) = delete;
T& operator=(T&& other) {x = other.x; std::cout << "move assigment\n";}
private:
int x;
};
int main() {
std::map<int, T> m;
m.insert(std::make_pair(42, T(24)));
m[44] = T(25);
}

Answer 3

You might insert as pointer:
public:
T(int v) : x(v) {};
int getX(){ return this->x; }
private:
T(const T &other); // disabled!
T &operator=(const T &other); // disabled!
int x;
};
int main()
{
std::map<int, T*> m;
m[42] = new T(24); // no compilation error here!
std::cout << m[42]->getX() << std::endl; // prints out 24
return 0;
}