> From: Bengt Gustafsson <bengt.gustafsson_at_[hidden]>

> 4. Allowing macro expansion. This is of course a more natural limitation
> for implementers considering the translation phase you are aiming at.
> But it is not as obvious for programmers who will certainly picture this
> as a purely textual transformation, which it basically is. Yes it is
> probably more work to do this in the earlier parts of the preprocessor,
> but not overly so. Note that R literals did force preprocessor
> implementations to be updated, it's not that we never touch the
> preprocessor.

I agree, it's going to cause surprise. But I think it's unavoidable.

For example:

    #define SOME_FLAG 42
    print(X"SOME_FLAG = { SOME_FLAG }");

The programmer will likely expect it to print "SOME_FLAG = 42".

But for it to do that, the preprocessor would need to look in the string, determine the "{}" replacement-field portion, and perform expansion within *only* that portion.

To make the preprocessor do such a thing, wouldn't that require WG14 to agree/approve?

And if so, wouldn't they just laugh me out of the room? (sorry, I don't know how those things go, but I assume it's... unlikely)

-hadriel



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