> Tom Lane writes: > The problem that I see after trying the experiment, however, is that > actually building Postgres using a C++ compiler would require changes > enormously more invasive than just renaming some fields and function > argument names. And I have no confidence in our ability to *keep* the > headers C++-clean if there's not a buildfarm member out there building > it with a C++ compiler so it can gripe about re-introduction of C++ > keywords. So I'm afraid the issue will just keep coming back.
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I never was talking about compiling the whole Postgres-implementation with g++ (even if that would nice experience :) It's only about a few header-files, were it would even be legal (but dirty) to patch them after compilation, since they are absolutely binary compatible. > Chuck mentioned the point that C++ rejects implicit casts from void* > to something else, but there are a lot of other problems, including > some that would require notational compromises I don't think we'd like > to make. Two examples: > * g++ rejects struct assignment if either source or destination is > accessed through a volatile pointer. We do that in a number of places, > mostly in xlog.c and bufmgr.c. Options I can see are not good: > 1: don't use volatile (not acceptable) > 2: cast away volatile (probably breaks the guarantee we want) > 3: do the assignment explicitly field-by-field (sucks from a > maintenance point of view, not to mention legibility) > 4: use memcpy (sucks for performance because structs are small, > and probably requires casting away volatile, see #2) > > * I don't see how to make expression_tree_walker and > expression_tree_mutator work reasonably nicely; g++ is too picky about > the argument types of the walker/mutator function. Only header files shall be C++ compatible. There is no reason and no need to make the whole implementation C++-conform. > Anyway, at this point my concern is not so much whether we could fix > it as what is the plan for keeping it fixed. A best practice statement, telling developers not use C++-keywords as identifiers in header-files. Regards, Jacob -- GMX FreeMail: 1 GB Postfach, 5 E-Mail-Adressen, 10 Free SMS. Alle Infos und kostenlose Anmeldung: http://www.gmx.net/de/go/freemail ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
