comp.lang.c++.moderated Google Group

Re: Hidden Features and Dark Corners of C++/STL

use_my_alias_h...@hotmail.com (DeMarcus) — Sun, 08 Nov 2009 15:52:02 UT

I didn't mean to be self-important, I actually haven't seen that
construction before. If I do this:
int* getintp() { return 0; }
if( int* i = getintp(), i != 0 )
{
then I get "error: expected ')' before ',' token" from gcc 4.3.2.
This compiles though:
int* i;
if( i = getintp(), i != 0 )
{

Re: solution for macro

b...@ingen.ddns.info (Bart van Ingen Schenau) — Sun, 08 Nov 2009 15:52:30 UT

dhun wrote:
To get the correct substitution for all macro parameters, you need
another two levels of macros.
This example give the required result:
int main(){
int a,a_b;
a = r(b);
Bart v Ingen Schenau

Re: Check .lib is complete

grahn+n...@snipabacken.se (Jorgen Grahn) — Sun, 08 Nov 2009 15:50:51 UT

...
You probably mean something like this (which by the way is likely to
work in various Unixes):
% nm -C libprefer.a | grep -iw U
Note that it's not enough; if the library contains foo.o and bar.o you
get to see foo.o's unresolved references to symbols in bar.o, and so
on. A static library (in the usual sense) doesn't have its internal

Re: #include file optimizer

smo...@exis.net (stan) — Sun, 08 Nov 2009 15:50:35 UT

That seems to get awfully close to makeing me understand
implementation details. When that class changes and no longer requires
<string> how will I know? I don't claim the impact of unecessary
headers is always a problem, but it will never be zero and it sure
seems like a suboptimal design to have unecessary headers or force me

Re: help on round robin tournament

ger...@gmail.com (mattia) — Sun, 08 Nov 2009 15:52:58 UT

Il Sat, 07 Nov 2009 18:24:03 -0600, red floyd ha scritto:
Well, I'm sorry you've misunderstood but I was asking for an advice, not
for homework (that I don't have since a long time ago). I've also said
that I'm a c++ novice, so I wated to know more about the OO programming
facing a simple problem that I was trying to solve.

Re: Mix Static and dynamic Polymorphism

b...@ingen.ddns.info (Bart van Ingen Schenau) — Sun, 08 Nov 2009 15:52:22 UT

Jun wrote:
Because PolicyA and Interface are two unrelated classes, the
PolicyA::execute() member will never be considered and overrider for
Interface::execute().
Base<T> remains an abstract class, because it does not have an overrider
for the pure-virtual member execute() that was inherited from Interface.

operator+() code for objects

andybolso...@yahoo.co.uk (silentway) — Sun, 08 Nov 2009 15:52:13 UT

I am trying to create a simple vector class with overloaded operators
for assignment, +=, -=, +, *, etc
My code for the overloaded operators worked OK, until I tried operator+
()
The problem is that I can not return a local variable. This is fair
enough, but I am sure that this used to work ok 10 years ago, when I

Re: References vs variables - speed impacts?

all...@tele.ntnu.no (Rune Allnor) — Sun, 08 Nov 2009 15:51:05 UT

It seem this is the crux. I reviewed the code, and found two
possible (and very likely) obstacles to removal of temporary
variables, which I depend on the compiler to do for me:
1) Type casts. The vector contains objects of that contain
a number of size_t pointers to other elements:
class element{

Re: Mix Static and dynamic Polymorphism

maxim.yegorush...@gmail.com (Maxim Yegorushkin) — Sun, 08 Nov 2009 00:24:34 UT

You could try inheritance chaining:
struct Interface {
virtual void run() = 0;
virtual void execute() = 0;
};
template<class Itf>
struct PolicyA : Itf {
void execute() {
// implementing Policy A;
}
};
template<class Itf>
struct PolicyB : Itf {
void execute() {

Re: Mix Static and dynamic Polymorphism

toh...@gmail.com (tohava) — Sun, 08 Nov 2009 00:24:14 UT

First, it would be wise to include the compilation errors.
Second, I'd recommend rewriting as:
struct Interface{
virtual void run(void) = 0;
virtual void execute(void) = 0;
struct PolicyA : public Interface {
void execute(){
// implementing Policy A;
}
struct PolicyB : public Interface {

Re: static_cast(signed type);

jaibudu...@gmail.com (Le Chaud Lapin) — Sun, 08 Nov 2009 00:24:26 UT

Seems that these questions and so many others can be answered by the C+
+0x draft document:
[link]
A trivial fact for those who wonder, as I did, what means the 'x' in 'C
++0x': It is a place-holder for single decimal digit 0-9, indicating
date of release of "specification", 2000-2009, respectively.

Re: When are data structures copied

maxim.yegorush...@gmail.com (Maxim Yegorushkin) — Sun, 08 Nov 2009 00:23:27 UT

Current STLPort-5.2.1 and STLPort 4 bundled with the latest Sun C++
compilers do not not use CoW. One most disappointing feature of STLPort
std::string is that the default constructor allocates storage, in other
words, a memory allocation is performed even for empty strings.
GNU std::string uses CoW. I hear that the standard interface of

Re: unsorted_set::erase not O(1) when nearly empty

maxim.yegorush...@gmail.com (Maxim Yegorushkin) — Sun, 08 Nov 2009 00:23:41 UT

There are interesting new (concurrent) implementations of hash tables
based on split-ordered lists. They store all elements in one long list,
so that iterating such a hash is the same as iterating a list. Google
for split-ordered list.

Re: help on round robin tournament

no.spam.h...@its.invalid (red floyd) — Sun, 08 Nov 2009 00:24:03 UT

[link]

solution for macro

mdhua...@gmail.com (dhun) — Sun, 08 Nov 2009 00:23:50 UT

Hi All,
I have a following kind of situation.
int main(){
int a,a_b;
a = r(b);
where I need to construct a symbol ab, at the place where code is
executed.
A g++ -E test.c, however insert a space between a and b.
What could be possible solution for this?