Tutorial by Examples: p

C++11 inline namespace includes the content of the inlined namespace in the enclosing namespace, so namespace Outer { inline namespace Inner { void foo(); } } is mostly equivalent to namespace Outer { namespace Inner { void foo(); } u...

Lambda expressions can be used to handle events, which is useful when: The handler is short. The handler never needs to be unsubscribed. A good situation in which a lambda event handler might be used is given below: smtpClient.SendCompleted += (sender, args) => Console.WriteLine("Ema...

public interface IShape { decimal Area(); } public struct Rectangle : IShape { public decimal Length { get; set; } public decimal Width { get; set; } public decimal Area() { return Length * Width; } }

The android:process field defines the name of the process where the service is to run. Normally, all components of an application run in the default process created for the application. However, a component can override the default with its own process attribute, allowing you to spread your applicat...

Django default project layout creates a single settings.py. This is often useful to split it like this: myprojectroot/ myproject/ __init__.py settings/ __init__.py base.py dev.py prod.py tests.py This enables...

SELECT FIND_IN_SET('b','a,b,c'); Return value: 2 SELECT FIND_IN_SET('d','a,b,c'); Return value: 0

package main import ( "log" "text/template" "os" ) type Person struct{ MyName string MyAge int } var myTempContents string= ` This person's name is : {{.MyName}} And he is {{.MyAge}} years old. ` func main() { t,err := temp...

Rcpp features two functions that enable code compilation inline and exportation directly into R: cppFunction() and evalCpp(). A third function called sourceCpp() exists to read in C++ code in a separate file though can be used akin to cppFunction(). Below is an example of compiling a C++ function w...

Rcpp Attributes makes the process of working with R and C++ straightforward. The form of attributes take: // [[Rcpp::attribute]] The use of attributes is typically associated with: // [[Rcpp::export]] that is placed directly above a declared function header when reading in a C++ file via sou...

Within C++, one can set different compilation flags using: // [[Rcpp::plugins(name)]] List of the built-in plugins: // built-in C++11 plugin // [[Rcpp::plugins(cpp11)]] // built-in C++11 plugin for older g++ compiler // [[Rcpp::plugins(cpp0x)]] // built-in C++14 plugin for C++14 standa...

In some cases you may want to wrap a synchronous operation inside a promise to prevent repetition in code branches. Take this example: if (result) { // if we already have a result processResult(result); // process it } else { fetchResult().then(processResult); } The synchronous and async...

When you want to use user generated content in the SQL, it with done with parameters. For example for searching user with the name aminadav you should do: var username = 'aminadav'; var querystring = 'SELECT name, email from users where name = ?'; connection.query(querystring, [username], functi...

a. Running multiple queries at same time All queries in MySQL connection are done one after another. It means that if you want to do 10 queries and each query takes 2 seconds then it will take 20 seconds to complete whole execution. The solution is to create 10 connection and run each query in a di...

You send the query as a string and in response callback with the answer is received. The callback gives you error, array of rows and fields. Each row contains all the column of the returned table. Here is a snippet for the following explanation. connection.query('SELECT name,email from users', fu...

Follow previous example of creating a seed. This example uses a MySQL Dump to seed a table in the project database. The table must be created before seeding. <?php use Illuminate\Database\Seeder; class UserTableSeeder extends Seeder { /** * Run the database seeds. * ...

git checkout --orphan new-orphan-branch The first commit made on this new branch will have no parents and it will be the root of a new history totally disconnected from all the other branches and commits. source

You may define scripts in your package.json, for example: { "name": "your-package", "version": "1.0.0", "description": "", "main": "index.js", "author": "", "license": &qu...

You can use a RecyclerView.ItemDecoration to put extra margins around each item in a RecyclerView. This can in some cases clean up both your adapter implementation and your item view XML. public class MyItemDecoration extends RecyclerView.ItemDecoration { private final int extraMargin; ...

Once your setup.py is fully functional (see Introduction), it is very easy to upload your package to PyPI. Setup a .pypirc File This file stores logins and passwords to authenticate your accounts. It is typically stored in your home directory. # .pypirc file [distutils] index-servers = py...

You can group multiple boolean logic statements within parenthesis in order to create a more complex logic evaluation, especially useful in if statements. if ((age >= 18 && height >= 5.11) || (status === 'royalty' && hasInvitation)) { console.log('You can enter our club'); ...