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Vagrant.configure("2") do |config| # ... other config up here config.vm.provider "vmware_fusion" end

vagrant up --provider hyperv

vagrant up --provider docker

vagrant up --provider vmware_fusion

vagrant up --provider vmware_workstation

vagrant up --provider virtualbox VirtualBox is the default provider for a vanilla Vagrant setup.

vagrant snapshot restore --no-provision mysnapshot

NSString *testString = @"There are 42 sheep and 8672 cows."; NSError *error = nil; NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"(\\d+)" options:NSRegularExpressionCaseIns...

Versions Release Date VersionRelease Date8.2.4December 07, 20167.53December 07, 20166.38 (unsupported)February 24, 20165.23 (unsupported)August 11, 2010 Entity types In earlier versions of Drupal, the field system was only used on content types. Now, thanks to the Entity API, we can add fields...

Make sure you have ruby installed before installing rubygems, and then: Installing RubyGems Using apt-get on Ubuntu sudo apt-get install rubygems Installing RubyGems Using yum sudo yum install rubygems Manual Installation Method wget https://rubygems.org/rubygems/rubygems-2.6.6.tgz tar xv...

Problem # models.py: class Library(models.Model): name = models.CharField(max_length=100) books = models.ManyToManyField(Book) class Book(models.Model): title = models.CharField(max_length=100) # views.py def myview(request): # Query the database. libraries = Librar...

Problem Django querysets are evaluated in a lazy fashion. For example: # models.py: class Author(models.Model): name = models.CharField(max_length=100) class Book(models.Model): author = models.ForeignKey(Author, related_name='books') title = models.CharField(max_length=100) ...

There are places in the standard where an object is copied or moved in order to initialize an object. Copy elision (sometimes called return value optimization) is an optimization whereby, under certain specific circumstances, a compiler is permitted to avoid the copy or move even though the standard...

C++17 Normally, elision is an optimization. While virtually every compiler support copy elision in the simplest of cases, having elision still places a particular burden on users. Namely, the type who's copy/move is being elided must still have the copy/move operation that was elided. For example:...

If you return a prvalue expression from a function, and the prvalue expression has the same type as the function's return type, then the copy from the prvalue temporary can be elided: std::string func() { return std::string("foo"); } Pretty much all compilers will elide the tempor...

If you return an lvalue expression from a function, and this lvalue: represents an automatic variable local to that function, which will be destroyed after the return the automatic variable is not a function parameter and the type of the variable is the same type as the function's return type ...

The bisect command helps you to track down the changeset that introduced a bug. Reset the bisect state and mark the current revision as bad (it contains the bug!) hg bisect --reset hg bisect --bad Go back to a point where you think the bug isn't present hg update -r -200 Now...

Python 2.x2.7 In Python 2 filter, map and zip built-in functions return a sequence. map and zip always return a list while with filter the return type depends on the type of given parameter: >>> s = filter(lambda x: x.isalpha(), 'a1b2c3') >>> s 'abc' >>> s = map(lambd...

In Python 3.x, the reduce function already explained here has been removed from the built-ins and must now be imported from functools. from functools import reduce def factorial(n): return reduce(lambda a, b: (a*b), range(1, n+1))

public class Foo { private CancellationTokenSource _cts; public Foo() { this._cts = new CancellationTokenSource(); } public void StartExecution() { Task.Factory.StartNew(this.OwnCodeCancelableTask, this._cts.Token); } public void Cance...