C++11: Rvalue References

In C++98,

references-to-non-const can bind to lvalues

references-to-const can bind to lvalues

references-to-const can bind to rvalues

In C++11, the following was added:

rvalue_references-to-non-const can bind to rvalues

rvalue_references-to-const can bind to rvalues

Here is an example:

int main()

 {

int                                           lvalue                                                                     = 3;

int                           &             xxxxxx_ref_to_non_const_bound_to_lvalue                = lvalue;

int const                 &             xxxxxx_ref_to_xxx_const_bound_to_lvalue = lvalue;

//             int                           &             xxxxxx_ref_to_non_const_bound_to_rvalue = 3; // Compile Error

int const                 &             xxxxxx_ref_to_xxx_const_bound_to_rvalue = 3;

//             int                           &&          rvalue_ref_to_non_const_bound_to_lvalue = lvalue; // Compile Error

//             int const                 &&          rvalue_ref_to_xxx_const_bound_to_lvalue  = lvalue; // Compile Error

int                           &&          rvalue_ref_to_non_const_bound_to_rvalue                = 3;

int const                 &&          rvalue_ref_to_xxx_const_bound_to_rvalue = 3;

    return 0;

}

Reference: https://isocpp.org/wiki/faq/cpp11-language#rval