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  1. #include <iostream>
  2. #include <memory>
  3. #include <functional>
  4. using namespace std;
  5.  
  6. int main() {
  7.  
  8.   unique_ptr<int> uptr = make_unique<int>(5566);
  9.   std::function<void()> func;
  10.   // 1. Why compile error... 
  11.   // func = std::bind([](unique_ptr<int> &&uptr2) {cout << *uptr2 << endl; }, std::move(uptr)); 
  12.   // func();
  13.   // 2. Why can I only write auto for deduction?
  14.   auto func2 = std::bind([](const unique_ptr<int>& uptr2/*no const is OK but why?*/)
  15.                            {	cout << *uptr2 << endl; },
  16.                          std::move(uptr)); 
  17.   // only can use "const &" to invoke func2?
  18.   // && or by value will compile error, but "&" can run successfully without reason....                         
  19.   func2();
  20.   auto func3 = std::bind([](unique_ptr<int> uptr2) {cout << *uptr2 << endl; }, std::move(uptr));
  21.   //func3(); // 3. How to invoke func3?... compile error
  22.  
  23.   return 0;
  24. }
Success #stdin #stdout 0s 3468KB
comments (?)
stdin 
Standard input is empty
stdout 
5566
https://ideone.com/99S4Qx
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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