To this day, I'm still having trouble remembering these names: lvalue, rvalue, prvalue, xvalue, glvalue.

While there was only lvalue, and rvalue - it was easy - LEFT and RIGHT - gives you the right intuition.

But now - if it has identity - "glvalue" - why not "ivalue" or "idvalue"?

And then can be moved - "rvalue" ? Why "rvalue", why not "mvalue", or "move-value"? Why the language have to be so constricted when comes to such an important bit - I mean we spell "value" fully, but miss the important bit...

Anyway just a rant... I'm having the same issue understanding "math" sometimes because of all the cryptic notations, and archaic symbols used.

▲ spacechild1 3 days ago | parent | next [-]

I think they wanted to preserve the meaning of the existing two value types. The naming is still bad, though, because it's inconsistent. For example, why should 'xvalue' belong to 'generalized lvalue' when it also belongs to 'rvalue'? Aren't 'l' and 'r' supposed to be opposites on the same dimension (movability)?

Here's a suggestion in retrospect:

         | ivalue  | pvalue
         ---------------------
  lvalue | ilvalue | (plvalue)
  rvalue | irvalue | prvalue

The current naming is confusing exactly because 'lvalue' should be a supertype in one dimension, just like 'rvalue', and not a subtype (here: 'ilvalue'). I think they took this shortcut because 'plvalue' doesn't really exist, but it's still inconsistent. Let's not even talk about 'xvalue' (here: 'irvalue').

▲ kccqzy 3 days ago | parent | prev [-]

I agree the names are confusing. But it's just a simple matter of having a diagram nearby to remember which is which. (I think I first saw that diagram on Stack Overflow.)

There have been a lot of times in science when I have trouble remembering names but have no trouble at all understanding the concepts behind these names. I just keep an index card nearby. I noticed this tendency of mine as early as high school. For example, in chemistry I sometimes couldn't remember which is dextro and which is levo, but I understand chirality and know how they are different. In physics I sometimes forget which is the magnetic B field and which is the magnetic H field, though I understand the difference between them. I don't use these concepts often so I haven't internalized the names. I think it's totally alright to have a name–concept dissociation for these.

	▲	malkia 3 days ago \| parent [-]
		I completely get it, that the language science has developed works great for it's own practicioners, but not really well for outsiders. Good luck explaining these "*values" to someone that hasn't touched C++ in a while. Then again other languages have the same peculiarities though. meh.