comp.lang.c++ Google Group

Re: map

2008-11-23T10:26:36Z

No, you have to use the make_pair() function:
cartesian_2d coord1 = make_pair(1,2);
cartesian_2d coord2 = make_pair(3,2);

Re: Who gets higher salary a Java Programmer or a C++ Programmer?

2008-11-23T10:02:46Z

That is a good plan in the short term, but don't think in terms of
picking one language to use for your whole career. There is no way to
know which languages will be popular in 40 years time.
...
High end programmer salaries depend on a lot of things, such as general
computer science knowledge, programming skill, luck, leadership skill,

Re: g++4.3.2 w/ c++0x: error: no type named ‘iterator’ in ‘class std::unordered_map<...'

2008-11-23T10:00:20Z

It just happened to work for std::map, even though it is not required.
The workaround would possibly be to store a pointer or a reference to
the cousin, instead of an iterator.
Bo Persson

Re: memcpy equivalent in C++

2008-11-23T09:53:23Z

Because they have heard that using memcpy will make their programs
extremely fast. And that this is very important.
Unfortunately they never heard anything about checking sizeof(dest)
first. :-(
Bo Persson

Re: Why the copy assignment operator is written to return non-const reference to this?

2008-11-23T09:41:45Z

Since when is it a bad practice? Operator overloading can help us hide
the fact that chaining is taking place but it's one of the prime
examples of when to use it.
Sure, there are times when it is bad style to use chaining, like some of
the cases you have shown, but I prefer consistency over special rules

Re: g++4.3.2 w/ c++0x: error: no type named ‘iterator’ in ‘class std::unordered_map<...'

2008-11-23T09:29:57Z

This may have changed in C++0X (I haven't checked), but in the 2003
standard what you are doing is undefined behavior. You cannot
instantiate a template component for any of the standard library
templates with an incomplete type. Within the definition of My_data,
My_data is an incomplete type.
Reference 17.4.3.6.2 in the 2003 standard.

Re: Opposite of ! operator.

2008-11-23T09:29:32Z

Your asking the wrong question. The real question is why you shouldn't
be allowed to overload the ! operator? Just because you can't find any
use for it does not mean that someone else can't, and remember, it does
not have to return a bool.

Re: Why the copy assignment operator is written to return non-const reference to this?

2008-11-23T09:27:08Z

Re: Why the copy assignment operator is written to return non-const reference to this?

2008-11-23T09:26:09Z

Since forever, of course. "Method chaining", just like everything in
C++, is a technique that can be used correctly or incorrectly. When used
correctly, it is a good practice.
... and there's absolutely no "abuse" in the above example, as far as
method chaining is concerned.
And? Obviously 'const' will not help here anyway.

Re: Why the copy assignment operator is written to return non-const reference to this?

2008-11-23T08:54:13Z

Since when method chaining is a good practice in C++? The whole point
of returning reference to this in the copy assignment operator is to
enable chaining of assignments, not to stack another thing to do
(member function calls for example). The const qualifier for the
return reference doen't solve the whole problem of calling member

Re: gotoxy in dev c++

2008-11-23T07:53:09Z

I have no personal experience with it, but sourceforge lists an ncurses
for Windows project.
<[link]>
Brian

Re: map

2008-11-23T07:46:11Z

On Sun, 23 Nov 2008 01:33:12 -0500, Kai-Uwe Bux <jkherci...@gmx.net>
wrote:
do i use these template lke this:
cartesian_2d coord1 = (1,2);
cartesian_2d coord2 = (3,2);
image_map map1;
map1.add(coord1, 1);
map1.add(coord2, 3);

Re: map

2008-11-23T06:33:12Z

[snip]
What about:
typedef int x_coordinate;
typedef int y_coordinate;
typedef std::pair< x_coordinate, y_coordinate > cartesian_2d;
typedef std::map< cartesian_2d, imageID > image_map;
Best
Kai-Uwe Bux

map

2008-11-23T06:02:13Z

I have an imageID and a pair of (X,Y) coordinate
how can I map( X,Y) coordinate as a key to imageID?
for example
(1,1) -> image1
(2,1) -> image5
(5,4) -> image12
(1,9) -> image8
... etc
what Class object i should use?
any example code ?

Re: The following code causes an infinite loop. Can you spot the problem and explain why?

2008-11-23T05:42:53Z

On Nov 23, 12:33 am, "doublemaster...@gmail.com"
Yes it does. It's syntactically incorrect (moreso, hard to understand)
as to why you'd have virtual function within the base class, when the
base class has the same name. The compiler (bad one) would not know
what to do since both are virtual, and both contain the same name