Which brings me to my question: since a function that takes an rvalue reference can take both rvalue references (unnamed temporaries) as well as lvalue references (named non-const references), is there any reason to use lvalue references anymore in function parameters? Shouldn't we always use...
The preceding examples ignore operator overloading, which is convenient syntax for a function call. “A function call is an lvalue if and only if the result type is a reference.” (C++03 5.2.2/10) Therefore, givenvector<int> v(10, 1729);,v[0]is an lvalue becauseoperator[]()ret...
c_str()); return 0; } As an interesting observation, on my machine clang++ -O3 generates 54 instructions for code above versus 62 instructions for regular std::min. However, with -O0 it generates 518 instructions for code above versus 481 for regular std::min. UPDATE For folks that d...
A reference is a name, so a reference bound to an rvalue is itself an lvalue (yes, L). (As only aconstreference can be bound to an rvalue, it will be aconstlvalue.) This is confusing, and will be an extremely big deal later, so I'll explain further. Given the functionvoid obs...
Inability to assign a non-constant lvalue reference of a certain type to an rvalue of a different type, Incompatible Type: Non-constant lvalue reference of 'A *' cannot be assigned to a value of 'std::shared_ptr', Inability to assign an rvalue of type 'i
(),stris a name, so it’s an lvalue. As I said above, “lvalueness versus rvalueness is a property of expressions, not of objects”. Of course, becausestrcan be bound to a temporary which will evaporate, its address shouldn’t be stored anywhere where it could be used afterobserve(...
C++03 3.10/1 says: "Every expression is either an lvalue or an rvalue." It's important to remember that lvalueness versus rvalueness is a property of expressions, not of objects. Lvalues name objects that persist beyond a single expression. For example, obj , *ptr...