c++

C++ -malign-double compiler flag

I need some help on compiler flags in c++. I'm using a library that is a port to linux from windows, that has to be compiled with the -malign-double flag, "for Win32 compatibility". It's my understanding that this mean I absolutely have to compile my own code with this flag as well? How about other .so shared libraries, do they have be r...

Replacement for vsscanf on msvc

Hi, I've run into an issue porting a codebase from linux (gcc) to windows (msvc). It seems like the C99 function vsscanf isn't available and has no obvious replacement. I've read about a solution using the internal function _input_l and linking statically to the crt runtime, but unfortunately I cannot link statically since it would mess...

How to work with a DATE type in a COM/ATL project

I've got an ATL method that takes a DATE type, which is really a double. I can't find the class/functions for this type. Does anyone know how to operate on this type? I just need to make it into something I can get into boost::gregorian::date (yyyy/mm/dd). Also, I would really like to know what this double represents. Thanks. ...

Looping on a closed range

How would you fix this code? template <typename T> void closed_range(T begin, T end) { for (T i = begin; i <= end; ++i) { // do something } } T is constrained to be an integer type, can be the wider of such types and can be signed or unsigned begin can be numeric_limits<T>::min() end can be numeric_limits<T>::max() (i...

Programmatically Installing Fonts

How could I programmatically install a font on the Mac platform (Snow Leopard)? What steps would I need to follow? I would like for the user to input a font file, then my software installs it. ...

Do Java or C++ lack any OO features?

I am interested in understanding object-oriented programming in a more academic and abstract way than I currently do, and want to know if there are any object-oriented concepts Java and C++ fail to implement. I realise neither of the languages are "pure" OO, but I am interested in what (if anything) they lack, not what they have extra. ...

How to switch iostream from binary to text mode and vice versa?

I want to read both formatted text and binary data from the same iostream. How can I do that? Why? Imagine this situation: You have different resources, and resource loaders for them, that take a std::istream as a parameter. And there are a "resource source" that provides these streams. Resources can be both text and binary and I need t...

CODE1 Spoj - cannot solve it

I am trying to solve the problem Secret Code and it's obviously math problem. The full problem For those who are lazy to go and read, it's like this: a0,a1,a2,...,an - sequence of N numbers B - some number known to us X = a0 + a1*B + a2*(B^2) + a3*(B^3) + ... + an*(B^n) So if you are given B and X, you should find a0,a1,..an. I don...

Visual packages in c++ for windows (i know i shouldn't use windows =( )

I use visual studio in several of my programming classes for c++, but after extensive searching on line i can't seem to find any decent graphics packages that are compatible with the software. i would hate to need to go out and buy Linux (Gnuplot is amazing i know) and this issue is frustrating. Any feedback would be greatly appreciated....

what is mistakes/errors in this code c++ tell me the correction ??

hello all here in this code the compiler print error : 132 C:.... `createlist' undeclared (first use this function) (Each undeclared identifier is reported only once for each function it appears in.) and repeat it again in all calls in main function :( what's the problem ?? plzzzz help me #include<iostream> #include<string> using nam...

Unable to capture standard output of process using Boost.Process

Currently am using Boost.Process from the Boost sandbox, and am having issues getting it to capture my standard output properly; wondering if someone can give me a second pair of eyeballs into what I might be doing wrong. I'm trying to take thumbnails out of RAW camera images using DCRAW (latest version), and capture them for conversi...

C++ Question on the pow function.

I'm trying to get this expression to work, I'm pretty sure its not the parenthesis because I counted all of them. Perhaps there something I'm doing wrong involving the parameter pow (x,y). double calculatePeriodicPayment() { periodicPaymentcalc = (loan * ((interestRate / yearlyPayment))) / (1-((pow ((1+(interestRate / yearlyPayment))...

How to properly downcast in C# with a SWIG generated interface?

I've got a very large and mature C++ code base that I'm trying to use SWIG on to generate a C# interface for. I cannot change the actual C++ code itself but we can use whatever SWIG offers in the way of extending/updating it. I'm facing an issue where a C++ function that is written as below is causing issues in C#. A* SomeClass::next(...

Is There a Good Pattern for Creating a Unique Id based on a Type?

I have a template that creates a unique identifier for each type it is instanced. Here's a streamlined version of the template: template <typename T> class arType { static const arType Id; // this will be unique for every instantiation of arType<>. } // Address of Id is used for identification. #define PA_TYPE_TAG(T) (&arType<T >::Id...

How do you do masked password entry on windows using character overwriting?

Currently I am using this implementation to hide user input during password entry: void setEcho(bool enable) { HANDLE hStdin = GetStdHandle(STD_INPUT_HANDLE); DWORD mode; GetConsoleMode(hStdin, &mode); if(enable) { mode |= ENABLE_ECHO_INPUT; } else { mode &= ~ENABLE_ECHO_INPUT; } SetConsoleMode(hStdin, mode); } ...

Can we overload a function based on only whether a parameter is a value or a reference?

I got the answer NO! Because passing by value and passing by reference looks identical to the caller. However, the code below compiles right class A { public: void f(int i) {} void f(int& i) {} }; But when I try to use it, there is compile error. int main () { A a; int i = 9; int& j = i; a.f(1); a.f(i); a.f(...

How to get this to compile?

I have this code which compiles and works as expected: class Right {}; class Left { public: Left& operator = (Right const&) { //... Do something ... return *this; } }; int main() { Right right; Left left; // Assign individual object -- this works left = right; } But now, this one surprises me, I thought the ...

Adjust parameters of serial port reading

Hello. I'm facing a particular issue that regards serial communication under win32. I'm communicating with a device can only accept frames when it is not already communicating. So I must find a valid frame and then inmediatelly send my request. I developed a class named Serial that handles basic operations on serial port (open, close, r...

C++ compile time purity checks?

Is it possible to specify compile time "purity" checks in C++? I.e.: this function does not read from anything other than it's arguments this function does not write to anything; it only returns the return value ...

Using type passed as a template in C++

Is it possible to actually use the type passed as a template for control flow? I'd like to write a function that uses templates, which in turn calls another function based on the type passed: template <class T> void test_function (T var) { //Do stuff if (T == char) { bar (var); } else { foo (var); } /...