为什么在const对象上调用std :: move会在传递给另一个对象时调用复制构造函数?具体来说,代码
#include <iostream>
struct Foo {
Foo() = default;
Foo(Foo && x) { std::cout << "Move" << std::endl; }
Foo(Foo const & x) = delete;
};
int main() {
Foo const x; Foo y(std::move(x));
}
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无法使用消息进行编译:
g++ -std=c++14 test07.cpp -o test07
test07.cpp: In function 'int main()':
test07.cpp:10:36: error: use of deleted function 'Foo::Foo(const Foo&)'
Foo const x; Foo y(std::move(x));
^
test07.cpp:6:5: note: declared here
Foo(Foo const & x) = delete;
^
Makefile:2: recipe for target 'all' …Run Code Online (Sandbox Code Playgroud)