Can anyone see a use for the "yield break" statement that could not have been otherwise achieved by using "break" or "return". This statement seems to be utterly useless. What's more, without this statement, the "yield return X" statement could have been simplified to "yield X", which much more readable. What am I missing? ...
What are the Advantages/Drawbacks of these two ways of iterating through a container / which one do you prefer and why: for (MyClass::iterator i = m.begin(), e = m.end() ; i != e ; i++) { // ... } or for (MyClass::iterator i = m.begin() ; i != m.end() ; i++) { // ... } Subsidiary question: i++ or ++i? Why? ...
I have 2 vector of with one has vec1{e1,e2,e3,e4} and the other one with vec2 {e2,e4,e5,e7} How to effectively get three vector from above vectors such that 1.has elements that is available only in vec1 similarly 2 has only vec2 elements and 3.with common elements ...
What are the common misuse of using STL containers with iterators? ...
Hi, When I use an Iterator of Object I use a while loop (as written in every book learning Java, as Thinking in Java of Bruce Eckel): Iterator it=... while(it.hasNext()){ //... } but sometime i saw than instead somebody use the for loop: Iterator it=... for (Iterator it=...; it.hasNext();;){ //... } I dont' understand this...
I have a map defined like this std::map<some_key_type, std::string::iterator> mIteratorMap; And a huge string named "mHugeString". Then I walk trough the string collecting iterators like this: std::string::iterator It=mHugeString.begin(); std::string::iterator EndIt=mHugeString.end(); for(;It!=EndIt;++It){ ...defining a key element...
Hi, I have a set of objects in a hierachy. There's a top "root" node and that has child nodes, which in turn have child nodes etc. I'm trying to save this structure into a DB using the nested set model, where each "side" of each node is numbered to define the hierarchy, as in: http://dev.mysql.com/tech-resources/articles/hierarchical...
Has anyone written or thought about writing an iterator for a composite (tree) structure without using recursion? If so can you share your ideas? Thks Edit: I was thinking of Java for lang. ...
Is there a simple built-in way to take an ordered list of IEnumerables and return a single IEnumerable which yields, in order, all the elements in the first, then the second, and so on. I could certainly write my own, but I wanted to know whether there was already a way to accomplish this seemingly useful task before I do it. ...
Hi all, This is a (hopefully) really simple question - I have been told recently that using C++ style initialisation is better than traditional (and more common) assignment. So this code: std::SomeSTLContainer::const_iterator it = container.begin(); std::SomeSTLContainer::const_iterator itEnd = container.end(); would be 'slower' or ...
I know find method finds the supplied key in std::map and return an interator to the element. Is there anyway to find the value and get an iterator to the element? What I need to do is to check specified value exist in std::map. I have done this by looping all items in the map and comparing. But I wanted to know is there any better appro...
I have a HashMap with millions of entries. Need to retrieve all entries whose keys match a specific set of criteria (in this case, each key is an object with two integer properties; I need to retrieve all keys where each of these integers fall within a specified range). What is the fastest, most efficient way to iterate through all suc...
Hi, I'm trying to get my head around using Iterators effectively in PHP 5, and without a lot of decent examples on the net, it's proving to be a little difficult. I'm trying to loop over a directory, and read all the (php) files within to search for defined classes. What I then want to do is have an associative array returned with the ...
If I have an IEnumerable like: string[] items = new string[] { "a", "b", "c", "d" }; I would like to loop thru all the pairs of consecutive items (sliding window of size 2). Which would be ("a","b"), ("b", "c"), ("c", "d") My solution was is this public static IEnumerable<Pair<T, T>> Pairs(IEnumerable<T> enumerable) { ...
Is there any way to use different types of iterators in different vectors? Or, is there a function that returns the position of element in vector as an integer? std::vector<DWORD>::iterator it; // Iterator // monsterQueue is a <DWORD> vector it = std::find(bot.monsterQueue.begin(), bot.monsterQueue.end(), object); // Check do w...
In C++, whenever a function creates many (hundreds or thousands of) values, I used to have the caller pass an array that my function then fills with the output values: void computeValues(int input, std::vector<int>& output); So, the function will fill the vector output with the values it computes. But this is not really good C++ style...
Is there a way to declare an iterator which is a member variable in a class and that can be incremented using a member function even though the object of that class is const. ...
I'm aware of the range iterators in boost, and as for this reference, it seems there should be an easy way of doing what I want, but it's not obvious to me. Say I want to represent a numerical range, 0 to 100 (inclusive or not), say range(0,100). I would like to do something like: for_each(range<int>(0,100).begin(), range<int>(0,100).e...
std::vector< std::vector<coords> >::iterator iter; for(iter = characters.begin(); iter != characters.end(); iter++) { std::vector<coords>* cha = iter; // doesn't work. } // does work. std::vector<coords>* character = &characters.at(0); coords* first = &character->at(0); And I don't get why. Isn't iter supposed to be a pointer to an ...
I'm trying to iterate over a directory which contains loads of PHP files, and detect what classes are defined in each file. Consider the following: $php_files_and_content = new PhpFileAndContentIterator($dir); foreach($php_files_and_content as $filepath => $sourceCode) { // echo $filepath, $sourceCode } The above $php_files_and_c...