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What exactly does Perl's “bless” do?
...to a hash (most common case), to an array (not so common), to a scalar (usually this indicates an inside-out object), to a regular expression, subroutine or TYPEGLOB (see the book Object Oriented Perl: A Comprehensive Guide to Concepts and Programming Techniques by Damian Conway for useful examples)...
super() raises “TypeError: must be type, not classobj” for new-style class
...pe(OldStyle()) is the instance type, which does inherit from object. Basically, an old-style class just creates objects of type instance (whereas a new-style class creates objects whose type is the class itself). This is probably why the instance OldStyle() is an object: its type() inherits from ob...
How to set versionName in APK filename using gradle?
...ind, but doesn't work well with flavors with different version codes. They all end up with same version code.
– weston
May 6 '17 at 15:08
2
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Why do we need extern “C”{ #include } in C++?
...
C and C++ are superficially similar, but each compiles into a very different set of code. When you include a header file with a C++ compiler, the compiler is expecting C++ code. If, however, it is a C header, then the compiler expects the data cont...
How to make rpm auto install dependencies
...hip and filesystem permissions:
# chown -R root.root /home/user/repo
Install the createrepo package if not installed yet, and run
# createrepo /home/user/repo
# chmod -R o-w+r /home/user/repo
Create a repository configuration file, e.g. /etc/yum.repos.d/myrepo.repo containing
[local]
name=My Aw...
Best way to do multiple constructors in PHP
...
<?php
class Student
{
public function __construct() {
// allocate your stuff
}
public static function withID( $id ) {
$instance = new self();
$instance->loadByID( $id );
return $instance;
}
public static function withRow( array $row ) {
...
What is the most efficient way to store a list in the Django models?
...
This is probably what I will end up doing, but I was really hoping the underlying structure for this would have been built in. I guess I am to o lazy.
– grieve
Jul 10 '09 at 16:11
...
How to make a cross-module variable?
...as if a global from any other module that includes __builtin__ -- which is all of them, by default.
a.py contains
print foo
b.py contains
import __builtin__
__builtin__.foo = 1
import a
The result is that "1" is printed.
Edit: The __builtin__ module is available as the local symbol __builtin...
What is the fastest way to get the value of π?
I'm looking for the fastest way to obtain the value of π, as a personal challenge. More specifically, I'm using ways that don't involve using #define constants like M_PI , or hard-coding the number in.
...
How many GCC optimization levels are there?
..., the default if no optimization level is specified)
-O1 (optimize minimally)
-O2 (optimize more)
-O3 (optimize even more)
-Ofast (optimize very aggressively to the point of breaking standard compliance)
-Og (Optimize debugging experience. -Og enables optimizations that do not interfere...