Tutorial by Examples: access

It is illegal to access a reference to an object that has gone out of scope or been otherwise destroyed. Such a reference is said to be dangling since it no longer refers to a valid object. #include <iostream> int& getX() { int x = 42; return x; } int main() { int& r...

Pair allows us to treat two objects as one object. Pairs can be easily constructed with the help of template function std::make_pair. Alternative way is to create pair and assign its elements (first and second) later. #include <iostream> #include <utility> int main() { std::p...

Copy the package installer unit file to /etc where changes will not be overwritten on an upgrade: cp /lib/systemd/system/docker.service /etc/systemd/system/docker.service Update /etc/systemd/system/docker.service with your options on ExecStart: ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0...

Xamarin.Forms provide great mechanism for styling your cross-platforms application with global styles. In mobile world your application must be pretty and stand out from the other applications. One of this characters is Custom Fonts used in application. With power support of XAML Styling in Xamar...

<?php use Symfony\Bundle\FrameworkBundle\Controller\Controller; use Symfony\Component\HttpFoundation\Request; class TestController extends Controller { //Inject Request HTTP Component in your function then able to exploit it public function myFunctionAction(Request $request) {...

Individual elements can be accessed through indexes. Python arrays are zero-indexed. Here is an example : my_array = array('i', [1,2,3,4,5]) print(my_array[1]) # 2 print(my_array[2]) # 3 print(my_array[0]) # 1

<!-- file.xml --> <people> <person id="101"> <name>Jon Lajoie</name> <age>22</age> </person> <person id="102"> <name>Lord Gaben</name> <age>65</age> ...

xcrun uses the system default Xcode version (set via xcode-select) to locate and execute command line tools from the Xcode application bundle, e.g., llvm-cov. # Generate code coverage reports via llvm-cov # /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin xc...

psycopg2 is the most popular PostgreSQL database adapter that is both lightweight and efficient. It is the current implementation of the PostgreSQL adapter. Its main features are the complete implementation of the Python DB API 2.0 specification and the thread safety (several threads can share t...

See discussions in "GRANT" and "Recovering root password".

You can allow role to access some action on resource by: $acl->allow('Administrator', 'products', 'create'); You can deny role to access some action on resource by: $acl->deny('Customer', 'categories', 'create'); You can check if role is allowed to some action on resource by using: $a...

When accessing a non-static member of an object through a pointer to member, if the object does not actually contain the member denoted by the pointer, the behavior is undefined. (Such a pointer to member can be obtained through static_cast.) struct Base { int x; }; struct Derived : Base { int y; ...

function getSheetData() { var sheet = SpreadsheetApp.getActiveSheet(); var startRow = 2; // First row of data to process var numRows = 100; // Number of rows to process var startCol = 1; //First column of data to process var numCols = 15; // Number of columns to process ...

The FileSystem API of Java 7 allows to read and add entries from or to a Zip file using the Java NIO file API in the same way as operating on any other filesystem. The FileSystem is a resource that should be properly closed after use, therefore the try-with-resources block should be used. Reading ...

If we know the desired URI of the document we are looking for: fn:doc("/stuff/mysimpledocument.xml") Returns the full document from the database, using the URI to locate it. Since this is XQuery, we can use XPath to find the document when we know about the structure, but not the URI: ...

In C#, an array name and a pointer to a data type same as the array data, are not the same variable type. For example, int *p and int[] p, are not same type. You can increment the pointer variable p because it is not fixed in memory but an array address is fixed in memory, and you can't increment th...

This example demonstrates how pointers can be used for C-like access to C# arrays. unsafe { var buffer = new int[1024]; fixed (int* p = &buffer[0]) { for (var i = 0; i < buffer.Length; i++) { *(p + i) = i; } } } The unsafe keyw...

C# inherits from C and C++ the usage of the symbol -> as a means of accessing the members of an instance through a typed pointer. Consider the following struct: struct Vector2 { public int X; public int Y; } This is an example of the usage of -> to access its members: Vector2...

Docstrings are - unlike regular comments - stored as an attribute of the function they document, meaning that you can access them programmatically. An example function def func(): """This is a function that does nothing at all""" return The docstring can ...

There are three ways you can access the Unity Asset Store: Open the Asset Store window by selecting Window→Asset Store from the main menu within Unity. Use the Shortcut key (Ctrl+9 on Windows / ⌘9 on Mac OS) Browse the web interface: https://www.assetstore.unity3d.com/ You may be prompted to...