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What is the performance cost of having a virtual method in a C++ class?
Having at least one virtual method in a C++ class (or any of its parent classes) means that the class will have a virtual table, and every instance will have a virtual pointer.
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Detect IF hovering over element with jQuery
...kyaJ/3/
(This only works when the selector matches ONE element max. See Edit 3 for more)
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Edit 1 (June 29, 2013): (Applicable to jQuery 1.9.x only, as it works with 1.10+, see next Edit 2)
This answer was the best solution at the time the question was answered. This ':hover' selector was remove...
IF… OR IF… in a windows batch file
Is there a way to write an IF OR IF conditional statement in a windows batch-file?
14 Answers
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Java HTTPS client certificate authentication
I'm fairly new to HTTPS/SSL/TLS and I'm a bit confused over what exactly the clients are supposed to present when authenticating with certificates.
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What's the Hi/Lo algorithm?
What's the Hi/Lo algorithm?
5 Answers
5
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Unnamed/anonymous namespaces vs. static functions
A feature of C++ is the ability to create unnamed (anonymous) namespaces, like so:
11 Answers
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Ukkonen's suffix tree algorithm in plain English
I feel a bit thick at this point. I've spent days trying to fully wrap my head around suffix tree construction, but because I don't have a mathematical background, many of the explanations elude me as they start to make excessive use of mathematical symbology. The closest to a good explanation that ...
What is 'Pattern Matching' in functional languages?
...plaining three parts:
Algebraic data types.
What pattern matching is
Why its awesome.
Algebraic data types in a nutshell
ML-like functional languages allow you define simple data types called "disjoint unions" or "algebraic data types". These data structures are simple containers, and can be re...
What's wrong with nullable columns in composite primary keys?
ORACLE does not permit NULL values in any of the columns that comprise a primary key. It appears that the same is true of most other "enterprise-level" systems.
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Can a foreign key be NULL and/or duplicate?
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Short answer: Yes, it can be NULL or duplicate.
I want to explain why a foreign key might need to be null or might need to be unique or not unique. First remember a Foreign key simply requires that the value in that field must exist first in a...