c++ - Difference in constructors with X() = delete; and private X(); -

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• which difference between declaring constructor private , =delete? 7 answers

let assume have class x , want wo explicitly forbid, let standard constructor. used long time in header file:

private:     x(); // 1. 

so, contructor disabled outside class, anybody. have learned in c++11 follwoing recommended:

x() = delete; // 2. 

both achive wish forbid standard contructor.

but exact difference bewteen them? why c++11 recommend last one? there other flags, signals set in 2. way?

example 1 way before had = delete came out in c++11. have = delete rid of constructor. making constructor private still use constructor in member function if try default object in member function = delete compiler error.

#include <iostream>  class foo {     foo(); public:     static void somefunc() { foo f; } };  class bar { public:     bar() = delete;     static void somefunc() { bar b; } };  int main() {     foo::somefunc();  // compile     bar::somefunc();  // compiler error } 

live example