c++

pinpointing "conditional jump or move depends on uninitialized value(s)" valgrind message

So I've been getting some mysterious uninitialized values message from valgrind and it's been quite the mystery as of where the bad value originated from. Seems that valgrind shows the place where the unitialised value ends up being used, but not the origin of the uninitialised value. ==11366== Conditional jump or move depends on unini...

GetLongPathName Undeclared

When I try to compile my code with the function GetLongPathName(), the compiler tells me that the function is undeclared. I have already read the MSDN documentation located @ http://msdn.microsoft.com/en-us/library/aa364980%28VS.85%29.aspx. But, even though I included those header files, I am still getting the undeclared function error....

Which file is the COM++ object and how do I import it to .NET?

I'm trying to write a COM++ object wrapper around a Qt widget (control) I wrote so I can use it in future .NET projects. e.g.: public __gc class comWidget; In the compile directory are the .exe, an exe.intermediate.manifest, and the comWidget.obj, and also some other crap files (.pdb, etc). So what/how do I import into .NET? I feel...

How to make a cell of TAdvStringGrid editable?

I am trying to implement a filter using the component TAdvStringGrid. My requirement is that I want the first row of this component to be editable when double clicked, so that the user can filter data. Borland C++ Builder is used to help achieve this task. I found this event OnCanEditCell. TCanEditCellEvent = procedure (Sender:TObject;...

C++ Returning a Reference

Consider the following code where I am returning double& and a string&. The thing works fine in the case of a double but not in the case of a string. Why is this difference in the behavior? In both the cases compiler does not even throws the Warning: returning address of local variable or temporary as I am returning a reference. #inclu...

Refcounted pointers on iPhone

1) Refcounted pointers need stack variables to have constructors / destructors called at predictable places. 2) Objective-C, afaik, does not support the above. 3) The cocoa libraries are bound in Objective-C, not C++. Thus, my question: is there a easy way to use the Cocoa libraries, yet still have most of my app in C++ (and thus use ...

GDI+ crashes when loading PNG from IStream

I wrote something to load PNG files from a custom C++ IStream via GDI+. It worked great until I ran it on Vista machines. Crashes every time. When compiled on VS 2008, I found that inserting code into the IStream::AddRef method, such as a cout, made the problem go away. When compiling with VS 2010, it still crashes regardless of that. ...

Why does this Object wonk out & get deleted ?

Stepping through the debugger, the BBox object is okay at the entry of the function, but as soon as it enters the function, the vfptr object points to 0xccccc. I don't get it. What is causing this ? Why is there a virtual table reference in there when the object is not derived from other class. (Though, it resides in GameObject from ...

Making use of C++ to speed up PHP

I saw this post on Sitepoint quoting a statement by Rasmus Lerdorf which goes (according to Sitepoint) as follows: How can you make PHP fast? Well, you can’t" was his quick answer. PHP is simply not fast enough to scale to Yahoo levels. PHP was never meant for those sorts of tasks. "Any script based language is simply not fast enough...

Simplest way to get current time in current timezone using boost::date_time ?

If I do date +%H-%M-%S on the commandline (Debian/Lenny), I get a user-friendly (not UTC, not DST-less, the time a normal person has on their wristwatch) time printed. What's the simplest way to obtain the same thing with boost::date_time ? If I do this: std::ostringstream msg; boost::local_time::local_date_time t = boost::local_t...

Template deduction based on return type?

I'd like to be able to use template deduction to achieve the following: GCPtr<A> ptr1 = GC::Allocate(); GCPtr<B> ptr2 = GC::Allocate(); instead of (what I currently have): GCPtr<A> ptr1 = GC::Allocate<A>(); GCPtr<B> ptr2 = GC::Allocate<B>(); My current Allocate function looks like this: class GC { public: template <typename T>...

All Audio frequencies.

How can I get(Is it possible?) all audio frequencies are now playing in the system for writing some sound visualizer? Is there any library c++ or c#? Thanks in advance ...

How to integrate ANTLR (2.7) in Visual Studio 2005 (C++) build?

I have a project containing files generated from a .g file (antlr 2.7.x). The guy who wrote the whole thing has left me with it. Until now, I did not need to modify the grammar and all was fine. But now, I cannot continue without modifying the grammar (i.e. the .g-file). I have the source code of the used antlr and the visual studio 200...

Using Library files in Linux

Hi Guys, Im trying to use some of the functions that are in the /lib/libproc-3.2.6.so library in my Ubuntu Distribution. I have downloaded and installed the header files and they are defined in my source files. Currently this is all im trying to do, just for starters... proc_t **read_proc = readproctab(0); But i get the following...

Casting pointer to object to void * in C++

I've been reading StackOverflow too much and started doubting all the code I've ever written, I keep thinking "Is that undefined behavour?" even in code that has been working for ages. So my question - Is it safe and well defined behavour to cast a pointer to an object (In this case abstract interface classes) to a void* and then later ...

how to pass a value to c++ from python and back?

i would like to pass values from python to a c++ program for an encryption from inside a python program and then return the value from there to the python program . how to do it? ...

What's wrong with these pointer initialization

char * a=0; int * b=0; cout<<a<<a+1; cout<<b<<b+1; what's wrong with it ...

what does this C++ line of code mean "sol<?=f((1<<n)-1,i,0)+abs(P[i])*price;"

Could anyone help me to understand following line of code: sol< ?=f((1<< n)-1,i,0)+abs(P[i])*price; I am studying an algorithm written using c++ and it has following operator < ?= . My problem is with understanding < ?= operator. Also when I compile this code using g++ compiler , it gives error message for above line of code line of c...

std::map keys in C++

I have a requirement to create two different maps in C++. The Key is of type CHAR* and the Value is a pointer to a struct. I am filling 2 maps with these pairs, in separate iterations. After creating both maps I need find all such instances in which the value of the string referenced by the CHAR* are same. For this I am using the follo...

Is this list-initialization of an array of unknown size valid in C++0x?

Is this list-initialization of an array of unknown size valid in C++0x? int main() { int x[]{0, 1,2,3,4}; return x[0]; } I believe it is valid, but would appreciate some confirmation. If anyone could quote from the C++0x-FCD to support their case, it would be greatly appreciated. Thanks! ...