Does std::move work with lvalue references? How does std::move work on standard containers?

Question

#include 

struct A { int a[100]; };

void foo (const A& a) {
  std::vector vA; 
  vA.push_back(std::move(a));  // how does move really happen         


        

Answer 1

Created a snippet to show it. Though in your example default constructor will be called, but you get the idea.

#include 
#include 

struct A { 
  int a[100];
  A() {}
  A(const A& other) {
    std::cout << "copy" << std::endl;
  }
  A(A&& other) {
    std::cout << "move" << std::endl;
  }
};

void foo(const A& a) {
  std::vector vA; 
  vA.push_back(std::move(a));
}

void bar(A&& a) {
  std::vector vA; 
  vA.push_back(std::move(a));
}

int main () {
  A a;
  foo(a);            // "copy"
  bar(std::move(a)); // "move"
}