reference

问题 I am writing a code to make a linked list. one of the function I wrote in order to make a linked list easier in the main function was[node is the name of a struct conatains a.data b.pointer name next) : node& create_node(int value) { node newitem; newitem.data=value; newitem.next=NULL; return (newitem); }; When I write the function like this everything is ok but I want to write the function header as : node * create_node(int value) But when I write it that way and I write return *newitem; I

问题 I understand that the semantics of equality checking changes based on whether you are checking value types or rference types. Aren't reference types just a higher level pointer? What exactly is happening when using a reference type? Is all the dereferencing, upcasting etc just being handled by the runtime now? 回答1: Yes, exactly, reference types are just "pointers" to memory that is managed by the garbage collector. C++: MyClass* mc = new MyClass(); Myclass* mc2 = mc; mc == mc2 // true, points

问题 The Iterator I'm writing is supposed to iterate through all fixed-sized connected subgraphs of another given graph. As these subgraphs are all very similar (only minor changes in a search-tree based algorithm), I don't want to create a new object to return on each call of next() because of runtime concerns. Therefore I have an object subGraph that is returned every time, but is changed by a function update() between calls of next() , so that the object works like a view of the current state

问题 I just solved some tasks about linked lists using Ruby. It was very interesting, but it requires a couple of new lines. Because if I pass head in some function, and change the head of the list, I have to return new head from method and reassign it to the variable. Because if I have a variable and I pass it to method, reassign a inside, outside a dose not changes: it "dose not changes if reassign variable in method" do a = [1,2] def reasign array array = [1] array end assert_equal [1], reasign

问题 Trying to install a package called BarcodeLib from the NuGet Package manager, but it fails with the following message: Could not install package 'BarcodeLib 2.2.1'. You are trying to install this package into a project that targets '.NETFramework,Version=v4.5', but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author. From the console: PM> Install-Package BarcodeLib -Version 2.2.1

问题 We have big project with many teams working on different modules and to keep 'master' always working we're using several team branches merged to the main branch in the end of every sprint if everything is OK. Every team have their feature branches that go to the team branch when they are finished. Now I try to move our project to the Gerrit to prohibit accidental direct pushes into 'master', but face several problems. I used Git a lot, but never used Gerrit before, so I'm little confused with

问题 I have a windows c++ dll which gets loaded by a third party program. I recently added a thread pool (this one https://github.com/progschj/ThreadPool/blob/master/ThreadPool.h). But now the dll get no longer unloaded when the third party program no longer needs it. The reason is that every thread spawned in the thread pool increases the dll reference count by one. One problem is that I don't know when the third party program no longer needs the dll, so I can't manually shutdown the thread pool

问题 I would like to better understand Python 3.x data model. But I do not find complete and precise explanation of Python Object behaviours. I am looking for references, it would be great if every case that I show below could be linked to a Python API reference or PEP or anything else valuable. Thank you further for your wise advises... Let say we have some complex Python structure for testing purposes: d1 = { 'id': 5432 ,'name': 'jlandercy' ,'pets': { 'andy': { 'type': 'cat' ,'age': 3.5 } ,'ray'

问题 I have written this program to find the first occurrence of the character in the user given string and frequency of that character. But when I print the value of variable i_r inside the main function it prints zero. But in side find_ch it shows right value. Why is this happening? #include<iostream> #include<string> using namespace std; string::size_type find_ch(string &str,char ch,int &i_r) { string::size_type first=0; for(auto i=static_cast<int>(str.size())-1;i>0;i--) { cout<<"Value of i_r :

问题 I'm a new Rust user and I'm reading a book The Complete Rust Programming Reference Guide . In the book there is an example: fn main() { let mut a = String::from("testing"); let a_ref = &mut a; a_ref.push('!'); println!("{}", a); } The book states the code will generate an error. However, on my local machine, I can run it without any issue. Is this because I'm using a newer Rust compiler [ rustc 1.41.0-nightly (412f43ac5 2019-11-24) ] and the code doesn't work on older ones? I've read some