Is there a performance difference between i++ and ++i in C++?

Is there a performance difference between i++ and ++i in C++?

We have the question is there a performance difference between i++ and ++i in C?What's the answer for C++? 1:[Executive Summary: Use ++i if you don't have a specific reason to use i++.]For C++, the answer is a bit more complicated.If i i

How do I check if an array includes an object in JavaScript?

How do I check if an array includes an object in JavaScript?

What is the most concise and efficient way to find out if a JavaScript array contains an object?This is the only way I know to do it:function contains(a, obj) { for (var i = 0; i < a.length; i++) { if (a[i] === obj) { r

Inconsistency in WPF command routing behavior depending on the UI focus state

Inconsistency in WPF command routing behavior depending on the UI focus state

I have a RoutedUICommand command which can be fired in two different ways:directly via ICommand.Execute upon a button click event;using declarative syntax: .The command is handled only by the top window: The first approach only works if

Using a filesystem::path, how do you open a file in a cross-platform way?

Using a filesystem::path, how do you open a file in a cross-platform way?

Let's say you have used the new std::filesystem (or std::experimental::filesystem) code to hunt down a file. You have a path variable that contains the full pathname to this variable.How do you open that file?That may sound silly, but consi

How to convert string to int64_t?

How to convert string to int64_t?

How to convert program parameter from argv to int64_t? atoi() is suitable only for 32 bit integers. 1:A C99 conforming attempt.[edit] employed @R. correction// Note: Typical values of SCNd64 include "lld" and "ld".#include #include int64

Rails force models to eager load

Rails force models to eager load

I would like to be able to load an entire app so that I may find the descendants of a given class.For example given I have the following class defined:# app/models/foo_class.rbclass FooClass It won't be found with:irb> ObjectSpace.each_obje

Variable template in template class - unexpected error (possible bug?)

Variable template in template class - unexpected error (possible bug?)

Having:struct Value{ template static constexpr T value{0};};(0)ideonetemplatestruct Something{ void x() { static_assert(TValue::template value == 0, ""); }};int main() { Something{}.x(); return 0; } Does not compile wi

Latest builds from Angular2 complain with: NgModule DynamicModule uses HomeComponent via “entryCompo

Latest builds from Angular2 complain with: NgModule DynamicModule uses HomeComponent via “entryCompo

Since switching to the latest builds of Angular 2 (i.e. on github, master), I get warnings as follows about all my components: NgModule DynamicModule uses HomeComponent via "entryComponents" but it was neither declared nor imported! This

c - warning: implicit declaration of function ‘printf’

c - warning: implicit declaration of function ‘printf’

I know alot of similar questions were asked before but i couldn't find something that would fix this warning i get:MyIntFunctions.c:19:2: warning: implicit declaration of function ‘printf’ [-Wimplicit-function-declaration]Occurs here:void I

Android - Using pipe between native and java apps

Android - Using pipe between native and java apps

I'm developing on SGS2 api v.16I have two applications: native and JavaFrom the native app I open a Unix pipe with mkfifo() function and write some string to it.And in the java app I'm trying to read the string, but somehow the app blocks a

Problem using a compare function inside of a class for sort()

Problem using a compare function inside of a class for sort()

If you take a look at my function CardCompare inside of the class... It doesn't work! But, if I instead use the function where it is commented out in Hand.cpp, it works perfectly fine. Why is this?Also, I am wondering if keeping the CardCom

gcc/ld - create a new libc.so with __isoc99_sscanf@@GLIBC_2.7 symbol from glibc.2.6

gcc/ld - create a new libc.so with [email protected]@GLIBC_2.7 symbol from glibc.2.6

I have an application, which does a error when I try to run it:/lib/libc.so.6: version `GLIBC_2.7' not foundBut the only symbol it needs from glibc 2.7 [email protected]@GLIBC_2.7 I want to write a small single function "library" with this

How to add URL to the trusted zone in Internet Explorer?

How to add URL to the trusted zone in Internet Explorer?

How can I add an URL to the trusted site? It seems that there are stored in the registry, but where exactly?The hints I've googled so far weren't helpfull.The .net programm will run locally on each client.Edit clarification: I want to do th

Getting user Idle time in C#?

Getting user Idle time in C#?

I found this tutorial on how getting Idle time of the user Idle Time.The problem is that it will only work if the application runs on the user.And my application runs on SYSTEM.How can I get the idle time? or if PC is idle? 1:As I unders

How do I get the header height of a Listview - c#

How do I get the header height of a Listview - c#

Can sombody tell me how to get the header height of a list view.Thanks 1:This might be a little bit hacky but you can do:listView.Items[0].Bounds.TopThis will only work if there is only one item in the list. So you might want to temporar

compile-time function for checking type equality

compile-time function for checking type equality

I need to implement self contained compile-time function for checking type equality (function template without arguments bool eqTypes()).self contained means not relying on library.I'm not good in all this. That's what I tried, but it's not

Java fatal error SIGSEGV

Java fatal error SIGSEGV

I am getting an error message from the Java compiler that I don't understand. I've tested my code on OSX 10.6, 10.9, and Ubuntu 14.04, with both Java 6 and 7. When I run with the Eclipse debugger or from the interpreter (using -Xint option)

How to use bind1st and bind2nd?

How to use bind1st and bind2nd?

I would like to learn how to use binding functions.Here is the idea:I have this function which takes to parameters:void print_i(int t, std::string separator){ std::cout And I would like to do:std::vector elements;// ...for_each(eleme

Why typedef can not be used with static?

Why typedef can not be used with static?

Why typedef can not be used with static? For example, the code below is an errortypedef static int INT2;What other rules should be follow to use the typedef? What other keywords can not be used with typedef? Thanks so much! 1:typedef do

How can I remove elements from a QList while iterating over it using foreach?

How can I remove elements from a QList while iterating over it using foreach?

I'm new to Qt and trying to learn the idioms.The foreach documentation says: Qt automatically takes a copy of the container when it enters a foreach loop. If you modify the container as you are iterating, that won't affect the loop.But it

ios - convert .m4a to .mp3 file programmatically

ios - convert .m4a to .mp3 file programmatically

Here i have m4a format audio, I need to convert into mp3 format.for this I used the code as - (void) toMp3{ NSString *m4aFilePath = pathToSave; NSString *mp3FileName = [NSString stringWithFormat:@"Audio%d",[audioArr count]]; mp3Fil

Google Maps API V3 Printing Maps

Google Maps API V3 Printing Maps

I am looking for a method to efficiently print Google maps that have been implemented on a site using the google maps api v3. I have seen some people using just the window.print js and then @media print{ body * { visibility: hidden; }

“points to uninitialised byte(s)” Valgrind errors

“points to uninitialised byte(s)” Valgrind errors

I've been using Valgrind to look for memory leaks in my code, and while no memory leaks are being found, some errors are reported all of them originating at a single function/class method:==17043== ERROR SUMMARY: 10100 errors from 3 context

How to avoid the error: terminate called after throwing an instance of 'std::logic_error'

How to avoid the error: terminate called after throwing an instance of 'std::logic_error'

if(player!=NULL) player->shuffled();I do such things to avoid passing a null reference to a string constructor, but when compiling it still comes to error. 1:Somewhere, somehow, you're calling the std::string constructor with the cons

How can I execute Javascript in my Delphi program without TWebBrowser?

How can I execute Javascript in my Delphi program without TWebBrowser?

I am working with a Web API that uses a Javascript interface to make requests, and the response is via a callback Javascript function. Is there a way to call Javascript code from Delphi without using a TWebBrowsercomponent? 1:You can al