I've got a static class member which is some container, like (Foo.h) class Foo { ... private: static list<string> s_List; } I need to populate the list with a number of specific values. Actually it should be also const, but that might overcomplicate the problem further. All the class member functions are static, so initializing...
The problem is pretty basic. (I am puzzled why the search didn't find anything) I have a rectangular "picture" that stores it's pixel color line after line in a std::vector I want to copy a rectangular region out of that picture. How would I elegantly code this in c++? My first try: template <class T> std::vector<T> copyRectFr...
basically i have (state, state code) pairs, that are subsets of country [USA] -> [VT] -> 32 so i'm using std::map<tstring<std::map<tstring, unsigned int>> but i'm having trouble with assignment of the state code for(std::map<tstring, std::map<tstring, unsigned int>>::const_iterator it = countrylist.begin(); it != countrylist.end(); ++i...
I'm working on a cross platform project that uses STL. The other compiler includes STL support by default, but in VS2005 I need to add the following before the class definitions that use STL items: #include <cstdlib> using namespace std; Is there a VS2005 option that would set this automatically? It's just a bit tedious to work around...
I want to be able to initialize a vector of a size 'SIZE' before main. Normally I would do static vector<int> myVector(4,100); int main() { // Here I have a vector of size 4 with all the entries equal to 100 } But the problem is that I would like to initialize the first item of the vector to be of a certain value, and the othe...
I am passed an Iterator and I have to pass it on to another function -- but filtered so that certain elements are skipped (it's a range of pointers, and I want to filter out the NULL pointers). I googled for "stl filter iterator" to see how to do this, and boost::filter_iterator came up. That looks nice and I could use it, but could ...
How could I free up a linked list that contains dynamically allocated objects? I try to use list<class*> lists, but then I could not use the insert() function to insert object to the list. Does anyone know what is the cause? ...
I'm trying to insert some value pairs into a std::map. In the first case, I receive a pointer to the map, dereference it and use the subscript operator to assign a value. i.e. (*foo)[index] = bar; Later, when I try to iterate over the collection, I'm returned key/value pairs which contain null for the value attribute in all cases ex...
I am bit confused about the difference between the usage of std::remove algorithm. Specifically I am not able to understand what is being removed when I use this algorithm. I wrote a small test code like this: std::vector<int> a; a.push_back(1); a.push_back(2); std::remove(a.begin(), a.end(), 1); int s = a.size(); std::vector<int>::...
I was trying to erase a range of elements from map based on particular condition. How do I do it using STL algorithms? Initially I thought of using remove_if but it is not possible as remove_if does not work for associative container. Is there any "remove_if" equivalent algorithm which works for map ? As a simple option, I thought of ...
When I use std::string and when char* to manage arrays of chars in C++? It seems you should use char* if performance(speed) is crucial and you're willing to accept some of a risky business because of the memory management. Are there other scenarios to consider? ...
Is there any easy way to view the data in an STL std::list<T> in the Metrowerks CodeWarrior debugger? I can view data near the beginning or end of the list by looking at expressions such as instances->__list_imp.__list_deleter.end_.compressed_pair_imp.second_.prev_->data_ I can expand the little '+' signs next to the struct members t...
Also, is there a cross-platform way to change the attribute of a file from read-only to writeable? Thanks much, Bert ...
I spent about 4 hours yesterday trying to fix this issue in my code. I simplified the problem to the example bellow. The idea is to store a string in a stringstream ending with std::ends, then retrieve it later and compare it to the original string. #include <sstream> #include <iostream> #include <string> int main( int argc, char** ...
I want to create a container which can associate a CLSID structure to something else (for example, a string); for example, std::map. (the CLSID means standard Windows CLSID structure) However when I want to use its find() and insert (object[clsid] = string), the STL just failed and gives errors. Does anyone know how to solve this? Fo...
Hello, Looking for a simple getline example which works correctly. I want to input something on the keyboard and assign it to a std::string, allowing for whitespace and tabs. The delimiter is the carriage return. TIA, Bert ...
Both should run in O(n log n), but in general sort is faster than stable_sort. How big is the performance gap in practice? Do you have some experience about that? I want to sort a very large number of structs that have a size of about 20 bytes. The stability of the result would be nice in my case, but it is not a must. At the moment the...
Just wondering, because of a problem I am running into, is it possible to create a vector of pointers? And if so, how? Specifically concerning using iterators and .begin() with it, ie: How would I turn this vector into a vector of pointers: class c { void virtual func(); }; class sc:public c { void func(){cout<<"using func...
I'm trying to determine whether an object is already contained within a std::set. According to msdn (and other sources) the set::find function is supposed to return end() if it doesn't find the element you asked for. However when I implement code like the following, set::find returns junk (0xbaadf00d) instead. set<Cell*> cellSet; Cell...
I want to do something like this: std::vector<int>::iterator it; // /cut/ search for something in vector and point iterator at it. if(!it) //check whether found do_something(); But there is no operator! for iterators. How can I check whether iterator points at anything? ...