lvalue

Learning the lvalue and rvalue. The definition is whatever that can be "address of" is the left value and otherwise, it is rvalue. I checked the operator precedence, both prefix and postfix increment has higher priority than the "address of" operator. For the following two examples, can anyone explain a bit why the first one "&++value1" is a lvalue while the second one "&value1++" is a rvalue. My wrong understanding for both case is: pValue1 is pointing to the value1 variable. No matter value1 is changed to 8 before or after the address correlation is built, the value1 variable always occupies

What is the reasoning behind the naming of "lvalue" and "rvalue" in C/C++ (I know how they function)? The standard mentions this: An lvalue (so called, historically, because lvalues could appear on the left-hand side of an assignment expression) [...] An rvalue (so called, historically, because rvalues could appear on the right-hand side of an assignment expression) [...] That is, an lvalue was something you could assign to and an rvalue was something you could assign from. However, this has gradually gotten further and further from the truth. A simple example of an lvalue that you can't

I was reading about const_cast operator in c++ 1.First weird thing thing i can't understand is const_cast operator syntax i.e. -const_cast--<--Type-->--(--expression--)-------------------->< what i have understand about this syntax is that it helps to cast away constness of an expression of type Type .But consider this code class ConstTest { private: int year; public: ConstTest() : year(2007) {} void printYear() const; }; int main() { ConstTest c; c.printYear(); return 0; } void ConstTest::printYear() const { ConstTest *c = const_cast<ConstTest*>(this); c->year = 42; std::cout << "This is the

I need some advice with this strange behavior – lets have this code: int ** p; This compiles without any trouble: p++; But this: ((int**)p)++; Gives me this error message: “error: lvalue required as increment operand” . I am casting to p to the type it already is, nothing changes, so what is the problem? This is simplified version of problem I came across, when I was trying to compile one old version of gdb . So I suppose, that this worked and something changed. Any idea what is wrong with the second example? Old versions of gcc support something called "lvalue casts" -- if you cast something

This question already has an answer here: Not able to understand error condition wrt lvalues 3 answers I have been trying to understand pointer concepts by writing simple code, and I got an error problem, and it seems like I couldn't solve it or understand it. #include <stdio.h> int *foo(void); int main(void) { printf("%d\n", *foo()); return 0; } int *foo(void) { static int num = 1; ++num; return &(++num); } Here is the error message. error: lvalue required as unary ‘&’ operand return &(++num); Function 'foo()' returns a pointer to int, and main is supposed to be print the returned int by