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From: philmasterplus on 23 Apr 2008 04:16
Here goes my list of questions that have been bugging me for a couple
of days.


1. It seems that console I/O with "cout <<" and "cin >>" results in a
bloated executable, whereas I/O functions from C such as printf() and
scanf() make smaller, faster programs. Are there any other C/C++
console I/O functions available, and which of them are fastest? Also,
do you think I should stick to cin and cout when regarding speed,
portability and the C++ philosophy?

2. I am using conio2.h from http://conio.sourceforge.net/ in my Visual
C++ 2008 projects to create a 16-color text user interface. Is there a
portable (for Windows, Linux, and Mac) alternative to conio2? I�d like
to have all functionality that conio2 provides. (The conio2 site
provides documentation.)

3. (If there is no suitable alternative to conio2) Microsoft Visual C+
+ Express 2008 seems to have a problem with structures. It gives a
syntax error with the following code:

someFunction(var1, var2, (COORD) {myInt1, myInt2});

And this one:

COORD cTemp = {0, 0};

To fix these issues (which came from the conio2 library mentioned
above), I have substituted the above to the below:

COORD cTemp; //Temporary measure for VCX 2008
cTemp.X = myInt1;
cTemp.Y = myInt2;
someFunction(var1, var2, cTemp);

Is there a way to eliminate the error without using temporary
variables?


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From: Christopher on 23 Apr 2008 16:07
On Apr 23, 2:16 pm, philmasterplus <philmasterp...(a)gmail.com> wrote:
> Here goes my list of questions that have been bugging me for a couple
> of days.
>
> 1. It seems that console I/O with "cout <<" and "cin >>" results in a
> bloated executable, whereas I/O functions from C such as printf() and
> scanf() make smaller, faster programs. Are there any other C/C++
> console I/O functions available, and which of them are fastest? Also,
> do you think I should stick to cin and cout when regarding speed,
> portability and the C++ philosophy?

What does size of the executable have to do with the speed at which it
executes?
It probably grew because it happened to be the first call to the
standard C++ library you made, which causes the library to link.
However, if you intend on writing C++, than surely you are going to
cause the link at some point. It would be pretty hard to write a C++
program without the C++ library.

> 2. I am using conio2.h fromhttp://conio.sourceforge.net/in my Visual
> C++ 2008 projects to create a 16-color text user interface. Is there a
> portable (for Windows, Linux, and Mac) alternative to conio2? I�d like
> to have all functionality that conio2 provides. (The conio2 site
> provides documentation.)

I don't know of any such libraries that change the colour of text on
in your DOS box. I highly doubt you would find anything from MS either
as they would be happy if the "console" did not exist at all.

> 3. (If there is no suitable alternative to conio2) Microsoft Visual C+
> + Express 2008 seems to have a problem with structures. It gives a
> syntax error with the following code:

> someFunction(var1, var2, (COORD) {myInt1, myInt2});

I doubt it has anything to do with your IDE. You are attempting to
cast something to a COORD without providing that something. Ask
yourself how the compiler is supposed to know what a {myInt1, myInt2}
is before it tries to cast it.

It looks like you are trying to do something like

someFunction(var1, var2, COORD(myInt1, myInt2));

where COORD has a constructor that takes an 2 int params while myInt1
and myInt2 are ints. If the definition of COORD doesn't provide that
for you and you can't change it, than do it the way you did declare it
outside the call, which is more readable anyway. What advantage do you
have in declaring a temporary in the call anyway? It still gets
created and set either way.


> And this one:
>
> COORD cTemp = {0, 0};

what is the definition of COORD?

> To fix these issues (which came from the conio2 library mentioned
> above), I have substituted the above to the below:
>
> COORD cTemp; //Temporary measure for VCX 2008
> cTemp.X = myInt1;
> cTemp.Y = myInt2;
> someFunction(var1, var2, cTemp);

That is more readable anyway.

> Is there a way to eliminate the error without using temporary
> variables?

You are making a temporary anyway, either way. Are you thinking that
just because you create something inside a function call that it
magically doesn't get constructed?

Maybe, maybe not. Depends if you on the definition of COORD and if you
can change it. A better question is why you would worry about having
the ability to construct something and assign values to it within the
function call rather than outside?


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From: Carl Barron on 23 Apr 2008 16:08
In article
<4ccb4779-b255-42f9-a3f2-384a2ea3cbac(a)56g2000hsm.googlegroups.com>,
philmasterplus <philmasterplus(a)gmail.com> wrote:

> Here goes my list of questions that have been bugging me for a couple
> of days.
>
>
> 1. It seems that console I/O with "cout <<" and "cin >>" results in a
> bloated executable, whereas I/O functions from C such as printf() and
> scanf() make smaller, faster programs. Are there any other C/C++
> console I/O functions available, and which of them are fastest? Also,
> do you think I should stick to cin and cout when regarding speed,
> portability and the C++ philosophy?
>
The C++ library footprint is ussually bigger than the C library
footprint, since the C++ library is in general more general. That
genealily is quite useful as soon as you get beyond built-in types and
'\0' terminated char arrays. I'd stick to std::cin/cout unless there is
a real reason to 'drop down' to the <cstdio> routines [essentially the C
IO library].

> 2. I am using conio2.h from http://conio.sourceforge.net/ in my Visual
> C++ 2008 projects to create a 16-color text user interface. Is there a
> portable (for Windows, Linux, and Mac) alternative to conio2? I'd like
> to have all functionality that conio2 provides. (The conio2 site
> provides documentation.)
>
16 color text is a platform dependent feature and not portable. So
the answer is compiler/platform specific, and the results vary.

> 3. (If there is no suitable alternative to conio2) Microsoft Visual C+
> + Express 2008 seems to have a problem with structures. It gives a
> syntax error with the following code:
>
> someFunction(var1, var2, (COORD) {myInt1, myInt2});
>
> And this one:
>
> COORD cTemp = {0, 0};
>
> To fix these issues (which came from the conio2 library mentioned
> above), I have substituted the above to the below:
>
> COORD cTemp; //Temporary measure for VCX 2008
> cTemp.X = myInt1;
> cTemp.Y = myInt2;
> someFunction(var1, var2, cTemp);
>
> Is there a way to eliminate the error without using temporary
> variables?

I am not familiar with MS 's conio stuff but I assume

struct COORD
{
int X;
int Y;
};

is the defintion cast in stone.

consider

struct my_coord:COORD
{
my_coord(int a,int b):X(a),Y(b){}
};

this is nothing but adding a ctor to COORD so slicing should not be
a problem. [Passing a my_coord as a COORD only passes the COORD
stuff not any thing added by my_coord.]

some_function(var1,var2,my_coord(myInt1,myInt2)); should work;

now all temps are compiler generated and are destructed upon the
completion of some_function().

if this does not compile without warnings then you could use

some_function(var1,var2,static_cast<COORD>(my_coord(myInt1,myInt2)));

although the static_cast is most likely not needed.

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