The example enable a client to iterate the internal std::vector using being() and end().
Code:
class foo {
public:
typedef std::vector<std::string>const_iterator iter;
iter begin () const;
iter end () const;
[Code] .....
In the future I see the need for this class to be able to control sequence (sorting) and also show a subset of the complete list based on a search parameter.
Using std::sort appear to solve the ability to sort the collection.
How can I return an iterator to the client which only iterates a sub-set of all items in the std::vector?
An example would be, I add this method to the class;
Code:
void find(const std::string& st);
So if the client performs (below) only items in std::vector that contains the character "a" should be possible to iterate.
Code:
foo f;
f.search("a");
One option would be to operate with two collection inside the foo class. One more static containing all items and the other containing the sorted and filtered items. This would lead to some copying but should work. Far from perfect.
I need to iterate through a vector in a const function, and, as my function is called very often, to get more performances I need my iterator to be declared somewhere else than the function, so it doesn't have to get deleted and recreated over and over again. So here is my code:
What happens is, after having called the collisionDestroy-function and the program tries to execute the nest loop in the outer for-loop, it all crashes with the text "Expression: vector iterator not decrementable", which I understand is because the iterator will have already become useless. The question is: know this, how do I fix it? I can't seem to get a hang of it.
Here's the collisionDestroy-function (the collisionReaction does nothing but sets a few local variables):
void Enemy::collisionDestroy(std::vector<Sprite*>& sprites) { for (std::vector<Sprite*>::iterator iter = sprites.begin(); iter != sprites.end(); iter++) { Enemy* tmp = dynamic_cast<Enemy*>(*iter); if (this == tmp && collisionType == 3 || collisionType == 1) { sprites.erase(iter); break; } } }
I am trying to make kind of a messenger using Socket/Network Programming
My program should allow clients to register or sign in, after they are signed in they should see a list of the other signed in people whoever I select from that list I should be able to implement using multiple threads as well.
I am programming an old-school dungeon crawler and thought it would be cool to get the pc's internal speaker in on the action. While Ive used the BEEP function to nice effect for generating music, how I would go about getting speech out of my internal speaker?
My prog name is test and the problem is when i compile it gives error : 'test' is not recognized as an internal or external command,operable program or batch file.
Code:
#include <stdio.h> #define ISDIGIT(y) ( y >= 48 && y <= 57 ) main( ) }
Is it possible to declare a struct/class, in a cpp file, designed for local use, but with internal linkage?
The usecase is that every once in a while, I want to wrap "startXXX+endXXX" function pairs in a simple RAII struct. I just declare the struct in my cpp and use it once.
However, if I do this, (AFAIK), the compiler will generate an entry in the link table, which means I could potentially have link conflicts if I declare the same struct twice in two different cpp files.
Unless I'm mistaken, since the struct is declared in the same cpp that it is used, I wouldn't need external linkage. Is there a way to avoid it?
I am using C++ new/delete operators to allocate/deallocate the buffers. I think for each allocated buffer, there should be an additional info block stores the size and other info about the buffer. How to know more details about this info block? I need to override these two operators and find such an info block is useful to my implementation.
working on this code I have encountered a few issues. My program lists the occurrence of each letter but i'm unsure of how to enable numeric variables. how to improve the overall quality of the code.
Code:
#include <stdio.h> #include <string.h> int main() { char string[100], ch; int c = 0, count[26] = {0}; printf("Enter a string
i have tried to search on the Internet but haven't found a suitable result that links in with what I want to do, that is to creation a WPF application and when you press a enable button it will enable the LAN and when I click the disable button it will disable the LAN until i click the enable button again. Now I know how to creation a WPF and the buttons, but how would I do the disabling LAN and enabling LAN?
By LAN i mean just the networking adapters, so that the PC cannot connect to a router and then the Internet.
I have ploughed through the exchanges in all the forums, yet I still cannot make it work. The following is a tiny Code::Blocks program, written to isolate the problem:
case ID_ENABLE is similar to case ID_DISABLE above, and neither works. case ID_MESSAGE and case ID_EXIT both works as expected.I have tinkered with EnableMenuItem(), but without success.
that successfully allows me to enable the function foo() only if FIRST is convertible to Base*, but I also only want foo() enabled if each type in REST... meets the same condition. What is the syntax for that? If no such syntax exists, how to achieve that effect?
I have a version of an app in 64bit but the problem is under program files on windows 8 64bit it doesn't have access to the programs files folder... usually virtualization will redirect it to the virtual store but with 64bit exe's this doesn't happen automatically. How do I enable it in code or in the manifest file?
From MSDN:
Virtualization is only enabled for:
32 bit interactive processes Administrator writeable file/folder and registry keys Virtualization is disabled for:
64 bit processes Non-interactive processes Processes that impersonate Kernel mode callers Executables that have a requestedExecutionLevel
Arrays are by far the most fun to work with and I really need see if its possible to enable an array to count apples, pears, peaches, from a group of three each.
If any of the fruit groups were chosen how might an algorithm be put together to count how many were chosen from each group. But lets take into consideration that these fruit groups are not supposed to be randomly generated, instead they belong as an array with certain amount of chosen occurrences. To show how many fruits were chosen from each group example, 1 from group 1, 2 from group 2, 3 from group 3 the out put is the important part because it shows the group and the occurrence of that group. the algorithm should be able to display the group with an occurrence as well
Using C . I have been tasked (for a University assignment) to create a program that will enable a user to upload an image and convert that image into ASCII text using SDL on a Linux system. I've managed to open a window, display an image (non-selected) and convert it into grayscale using
case SDLK_g: for (int y = 0; y < image->h; y++) { for (int x = 0; x < image->w; x++) { Uint32 pixel = pixels[y * image->w + x]; Uint8 r = pixel >> 16 & 0xFF; Uint8 g = pixel >> 8 & 0xFF; Uint8 b = pixel & 0xFF; Uint8 v = (0.212671*r)+(0.715160*g)+(0.072169*B)/>; pixel = (0xFF << 24) | (v << 16) | (v << 8) | v; pixels[y * image->w + x] = pixel;
I am absolutely clueless as to how I can get the user to upload an image to the program and then begin the image -> ASCII conversion. I've found seem to be written in C++ or C# to make the conversion I should be using the GetPixelColour command?
#include <stdio.h> #include <tchar.h> #include <iostream> #include <string> #include <fstream>// enable writing to and reading from files #include <cstdlib> #include <time.h> using namespace std; class Person {
[Code] .....
Error list:
Code:
Error 1 error LNK2019: unresolved external symbol "void __cdecl saveperson(void)" (?saveperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 2 error LNK2019: unresolved external symbol "void __cdecl displayperson(void)" (?displayperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 3 error LNK2019: unresolved external symbol "void __cdecl editperson(void)" (?editperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 4 error LNK1120: 3 unresolved externals H:Cry_DevProgrammingC++Using_class_ in_ c++DebugUsing_class_ in_ c++.exe 1
So I have a vector that I want to iterate through randomly, and by random I mean that each element is only accessed once but I don't want to shuffle the vector because the vector elements are large. So I want this functionality:
std::vector<SomeLargeObjectWithoutACopyConstructor> myvec; // ...fill myvec std::random_shuffle(myvec.begin(),myvec.end()); for (auto& value : myvec) { // do stuff }
Only I don't want to do this because the object type has no copy constructor and is large, so I don't want to shuffle the vector, just the iteration path. Is there a simple and efficient way of iterating randomly through a vector while ensuring that each object is only accessed once?
Lexer.cpp: In member function 'void Lexer::PrintSource()': Lexer.cpp:29:42: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'begin' for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++) ^ Lexer.cpp:29:76: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'end' for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++) ^
How can a set a pointer , to a matrix example matrix[20][20] and iterate ( loop ) in each row first sort of X first and then Y through it using the pointer , how to setup dynamic allocation
through pointer = new matrix[20][20]
and finally call delete on pointer when done with the matrix.
I need to allow the user to input an integer of any length and print out the word of each number in the integer. So the user would enter "324562" and then the output would be "three two four five six two". I'm struggling to understand the best way to do it in C. I know I need a loop that goes through the int but I don't know how to do it
A C++ container type called std::map is used to store elements that are formed by a combination of key value and mapped value. How do you iterate through this container and find the value mapped to a specific key?
I'm having trouble getting my loop to work correctly. If I iterate the for loop once it works as expected and displays proper output. When I try to iterate two times or more the program gets stuck in an infinite loop.
I need to use dynamic memory allocation and use pointers to iterate through the arrays that I have already in this program. I am lost, nothing I do works and where to use the pointers. I am just looking for a push in the right direction so I can finish this project and how I can implement pointers in my program.
