c++

Of these 3 methods for reading linked lists from shared memory, why is the 3rd fastest?

I have a 'server' program that updates many linked lists in shared memory in response to external events. I want client programs to notice an update on any of the lists as quickly as possible (lowest latency). The server marks a linked list's node's state_ as FILLED once its data is filled in and its next pointer has been set to a valid ...

Is there a difference between boost iostream mapped file and boost interprocess mapped file?

I want to create a mapped binary file into memory; however I am not sure how to create the file to be mapped into the system. I read the documentation several times and realize there are 2 mapped file implementations, one in iostream and the other in interprocess. Do you guys have any idea on how to create a mapped file into shared mem...

More with eclipse cdt

What is done when we import an existing project(maybe a visual studio project)? Which files are used for configuration? ...

How can I round money values to the nearest $5.00 interval?

I have an Informix-SQL based Pawnshop app which calculates an estimate of how much money should be loaned to a customer, based on the weight and purity of gold. The minimum the pawnshop lends is $5.00. The pawnshop employee will typically lend amounts which either ends with a 5 or 0. examples: 10, 15, 20, 100, 110, 125, etc. They do thi...

How might I wrap the FindXFile-style APIs to the STL-style Iterator Pattern in C++?

Hello everyone :) I'm working on wrapping up the ugly innards of the FindFirstFile/FindNextFile loop (though my question applies to other similar APIs, such as RegEnumKeyEx or RegEnumValue, etc.) inside iterators that work in a manner similar to the Standard Template Library's istream_iterators. I have two problems here. The first is w...

Intermediate values in C++

Hello. I can not find how to implement a design in C++. In the language of Delphi in case the operator can write the following design: case s[j] of '0'..'9','A'..'Z','a'..'z','_': doSomeThing(); How can i do the same in c++. Attracts me is the construction type 'a' .. 'z' and etc... Thank you ...

question regarding "this" pointer in c++

hello there, i have been given class with int variables x and y in private, and an operator overload function, class Bag{ private: int x; int y; public: Bag(); ~Bag(); //....... //.....etc }; Bag operator+ (Bag new) const{ Bag result(*this); //what does this mean? result.x += new.x; resul...

Why data members are private by default in C++?

Hi, Is there any particular reason for having all data members in a class as private by default in C++? Thanks, Naga ...

Getting segmentation fault after destructor

I'm making a small file reading and data validation program as part of my TAFE (a tertiary college) course, This includes checking and validating dates. I decided that it would be best done with a seperate class, rather than integrating it into my main driver class. The problem is that I'm getting a segmentation fault(core dumped) afte...

Failed to link mysql5.1.39\bin\libmySQL.dll

When trying to link to mysql5.1.39\bin\libmySQL.dll, I get an error: fatal error LNK1107: invalid or corrupt file: cannot read at 0x2D0 Anyone familiar with this? ...

How to compile and build c++ application with hand written makefile in windows?

Can someone provide a HelloWorld demo ? ...

When is .h not needed to include a header file?

This works: #include <iostream> using namespace std; but this fails: #include <stdio> When is .h not needed? About the namespace issue,I didn't find such logic in cstdio: #pragma once #ifndef _CSTDIO_ #define _CSTDIO_ #include <yvals.h> #ifdef _STD_USING #undef _STD_USING #include <stdio.h> #define _STD_USING #else /* _STD_...

Conversion of pointer-to-pointer between derived and base classes?

Regarding the following C++ program: class Base { }; class Child : public Base { }; int main() { // Normal: using child as base is allowed Child *c = new Child(); Base *b = c; // Double pointers: apparently can't use Child** as Base** Child **cc = &c; Base **bb = cc; return 0; } GCC produces the foll...

Subclassing and adding data members

I have an hierarchy of classes that looks like the following: class Critical { public: Critical(int a, int b) : m_a(a), m_b(b) { } virtual ~Critical() { } int GetA() { return m_a; } int GetB() { return m_b; } void SetA(int a) { m_a = a; } void SetB(int b) { m_b = b; } prot...

C++ struct, public data members and inheritance

Is it ok to have public data members in a C++ class/struct in certain particular situations? How would that go along with inheritance? I've read opinions on the matter, some stated already here http://stackoverflow.com/questions/952907/practices-on-when-to-implement-accessors-on-private-member-variables-rather-than http://stackoverflow...

C++ Professional Code Analysis Tools

Hello there, I would like to ask about the available (free or not) Static and Dynamic code analysis tools that can be used to C++ applications ESPECIALLY COM and ActiveX. I am currently using Visual Studio's /analyze compiler option, which is good and all but I still feel there is lots of analysis to be done. I'm talking about a C++ ap...

Why dll can't be used in c++?

It's pointed out by this answer: http://stackoverflow.com/questions/2532280/failed-to-link-mysql5-1-39-bin-libmysql-dll-in-a-c-project/2532382#2532382 But I don't understand why,.dll is essentially the same as .lib except for there is only one copy of it used by different processes. Does it have anything to do with the IDE?I'm using v...

What does using mean in c++?

Like : using ::size_t; using ::fpos_t; using ::FILE; In fact it's a question inspired by the comment under this question: http://stackoverflow.com/questions/2532412/when-is-h-not-needed-to-include-a-header-file ...

Remove from a std::set<shared_ptr<T>> by T*

I have a set of shared pointers: std::set<boost::shared_ptr<T>> set; And a pointer: T* p; I would like to efficiently remove the element of set equal to p, but I can't do this with any of the members of set, or any of the standard algorithms, since T* is a completely different type to boost::shared_ptr<T>. A few approaches I can t...

How does one force construction of a global object in a statically linked library? [MSVC9]

I have a global list of function pointers. This list should be populated at startup. Order is not important and there are no dependencies that would complicate static initialization. To facilitate this, I've written a class that adds a single entry to this list in its constructor, and scatter global instances of this class via a macro wh...