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E.g.
double dbInf=1/sin(0);
currently I check it as:
//=====================
char sz[4096];
sprintf(sz,"%f",dbInf);
if(strchr(sz,'#')) //true means the double is infinite number.
//========================
in my program, I have million of doubles needed to be checked, above checking code is very slow.
my Q is:
how to check it directly without using sprintf() and strchr()?
or how to check it faster?
thx.
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There is the CRT function _finite(double)[^], but it is not working.
Maxwell Chen
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#include <math.h>
#include <float.h>
...
double dbInf = 1.0 / sin((double)0);
if (0 == _finite(dbInf))
{
}
Mark Salsbery
Microsoft MVP - Visual C++
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I tried to run my ActiveX-embled MFC Application on Computer with out VC++ install and It doesn't work
But It work on another computer with vc++ 6.0 installed
Can someone suggest the solution?
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Register that ActiveX control with regsvr32.exe.
Maxwell Chen
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Hello everybody,
Is there any documention around which describes the name mangling sheme of this sw.
I googled around but found nothing useful.
I have a .dll which is compiled within the same solution and it exports the functions as "functionname" without leading
underscore
In the same solution I want to use this .dll as a lib for a normal .exe and this insists that to link to
"_functionname" (with underscore) which is of course not found in the .dll/.lib
The functions are decleared as extern "C" as usual and also the __declspec(dllexport) is like normal.
Anybody any idea?
bb |~ bb
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Harald Krause wrote: Is there any documention around which describes the name mangling sheme of this sw.
Microsoft Visual C++ Name Mangling[^]
Harald Krause wrote: I have a .dll which is compiled within the same solution and it exports the functions as "functionname" without leading
underscore In the same solution I want to use this .dll as a lib for a normal .exe
You have to view the actual export symbols with the tool "Dependency Walker".
Harald Krause wrote: this insists that to link to
"_functionname" (with underscore) which is of course not found in the .dll/.lib
The functions are decleared as extern "C" as usual and also the __declspec(dllexport) is like normal.
This is the standard pure C export behavior.
Maxwell Chen
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How to treat Image files in drawing DFD, as Entity or as Data Store...?
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is there any tool in MS Visual Studio to obtain Class Digrams of the classes we have created in VC++..?
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I have a basic OOP question I have a Base class lets I'll call it B
I am going to add functionality to this in addition I will need to use multiple copies of the
Base class
My question is What is the best programming approach
CLass A : B
{
OR
CLass A
{
B mybclass[10];
Thankx in advance
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ForNow wrote: What is the best programming approach
No one can say that once and for all.
The classical oO-analysis question would be: IS every A also a B in every respect?
Or does it HAVE a B, that is, does it use a B to do its work.
Though I speak with the tongues of men and of angels, and have not money, I am become as a sounding brass, or a tinkling cymbal. George Orwell, "Keep the Aspidistra Flying", Opening words
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The Latter is true A is B plus a whole lot more However in addition to that A is multiple occurences of B
Thankx
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ForNow wrote: My question is What is the best programming approach
The difference requires context that you have not supplied. Your question as posted is not possible to answer.
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i don't understand what the question is??
if you have an Animal base class and you want to derive a Dog from it
surely you would put
class Dog : public Animal<br />
{<br />
};
or is that not the question you're asking? i am only a learner myself but if you're asking is it right or wrong, no there is no answer whichever you're most comfortable with
hth
paul
if ignorance is bliss then knock the smile off my face!!!
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1slipperyfish wrote: but if you're asking
I didn't ask anything so I have no idea what your post is supposed to mean for me.
1slipperyfish wrote: no there is no answer whichever you're most comfortable with
If that is directed at the original question, "To inherit or to aggregate", it is not a valid answer.
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sorry led mike i thought you just posted and it joined the rest i wasn't posting to you why wouldn't you inherit?
paul
if ignorance is bliss then knock the smile off my face!!!
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1slipperyfish wrote: why wouldn't you inherit?
You are just not following the thread.
Your post used classes "Animal" and "Dog" which provide "context" and obviously a Dog "is a" Animal thereby indicating inheritance.
However, the original poster used the classes "A" and "B" which provide no context and therefore we cannot distinguish between "is a" or "has a".
By the way Mark wants to have lunch with you.
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i thought that was what was happening and wondered why use A and B?? i am only a learner myself
i am on leave all week so any day suits me
paul
if ignorance is bliss then knock the smile off my face!!!
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led mike wrote: I didn't ask anything so I have no idea what your post is supposed to mean for me.
I chuckled at the irony (or is it coincidence) in the user name
Mark Salsbery
Microsoft MVP - Visual C++
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The best exmaple I could give if B is car then A is a fleet of cars with all the options
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In that case, your second example (which is neither derived or multiple base classes).
'A' has a fleet (array) of cars but it is not a car.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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okay thankx its hard to get into OO thinking
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If it helps any:
"Is ..." Use inheritance
"Has ..." Add a member
Example:
given a base class fruit
class apple - apple "is" a fruit so derive apple from fruit
class fruitbasket - a fruit basket "has" fruit so add fruit (or an array of fruit) as a member of the fruitbasket class
Mark
Mark Salsbery
Microsoft MVP - Visual C++
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