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Why do we need a pure virtual destructor in C++?
...class Base
{
public:
Base();
virtual ~Base() = 0; // Pure virtual, now no one can create the Base Object directly
};
Base::Base() { cout << "Base Constructor" << endl; }
Base::~Base() { cout << "Base Destructor" << endl; }
class Derived : public Base
{
public:
...
Polymorphism with gson
...
RuntimeTypeAdapter is now complete, unfortunately it doesn't look like it's in Gson core yet. :-(
– Jonathan
Aug 14 '13 at 12:52
...
“git rm --cached x” vs “git reset head -- x”?
... commit it, you add it to the tree as well.
It will probably help you to know the three more common flags in git reset:
git reset [--<mode>] [<commit>]
This form resets the current branch head to <commit> and possibly
updates the index (resetting it to the tree of <...
Declaring variables inside loops, good practice or bad practice?
... be mitigated using the -Wshadow warning instruction on GCC)
The compiler knows that the variable scope is limited to inside the loop, and therefore will issue a proper error message if the variable is by mistake referenced elsewhere.
Last but not least, some dedicated optimization can be performed ...
Nginx no-www to www and www to no-www
...r_name google.com;
index index.php index.html;
####
# now pull the site from one directory #
root /var/www/www.google.com/web;
# done #
location = /favicon.ico {
log_not_found off;
access_log off;
}
}
...
Does setting Java objects to null do anything anymore?
...ue. Basically, because you've preallocated an array, the VM sees that. It knows nothing about the "logical" size of your container. Say you have an ArrayList of size 10, backed by a 16-element array. The VM can't know that items 10..15 aren't actually used; if those slots have contents, they will no...
Python class inherits object
...problem…
Python introduced new-style classes back in Python 2.2, and by now old-style classes are really quite old. Discussion of old-style classes is buried in the 2.x docs, and non-existent in the 3.x docs.
The problem is, the syntax for old-style classes in Python 2.x is the same as the alter...
Is SQL syntax case sensitive?
...on Linux MySQL and case-insensitive used to be the default on Windows, but now the installer asked about this during setup. For MSSQL it is a function of the database's collation setting.
Here is the MySQL page about name case-sensitivity
Here is the article in MSDN about collations for MSSQL
...
Targeting both 32bit and 64bit with Visual Studio in same solution/project
..., even on 64-bit machines.
This may be fixed in a future release, but for now (or when using a different tool to create your MSIs that has the same issue), you can use WiX 3.0's managed custom action support to create action DLLs with the proper bitness that will be executed using the corresponding...
How do I install Maven with Yum?
...-maven/epel-apache-maven.repo -O /etc/yum.repos.d/epel-apache-maven.repo
Now you can install maven like this:
yum install apache-maven
Once done, maven 3 will be installed and mvn -version will show you which version you've got - I had 3.2.1.
This worked perfectly for me on CentOS 6 with one e...