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Pure virtual function with implementation
...he base type can still define an implementation. A derived class can explicitly call the base class implementation (if access permissions allow it) by using a fully-scoped name (by calling A::f() in your example - if A::f() were public or protected). Something like:
class B : public A {
virtu...
Do HTML WebSockets maintain an open connection for each client? Does this scale?
I am curious if anyone has any information about the scalability of HTML WebSockets. For everything I've read it appears that every client will maintain an open line of communication with the server. I'm just wondering how that scales and how many open WebSocket connections a server can handle. Mayb...
Placement of the asterisk in pointer declarations
...ng I do not really understand about pointers or more precisely, their definition.
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With CSS, use “…” for overflowed block of multi-lines
with
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How can you do anything useful without mutable state?
...of stuff about functional programming lately, and I can understand most of it, but the one thing I just can't wrap my head around is stateless coding. It seems to me that simplifying programming by removing mutable state is like "simplifying" a car by removing the dashboard: the finished product ma...
Rails: FATAL - Peer authentication failed for user (PG::Error)
... on your server then just host: localhost to database.yml, I usually throw it in around where it says pool: 5. Otherwise if it's not localhost definitely tell that app where to find its database.
development:
adapter: postgresql
encoding: unicode
database: kickrstack_development
host: loca...
How can I pretty-print JSON in a shell script?
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With Python 2.6+ you can just do:
echo '{"foo": "lorem", "bar": "ipsum"}' | python -m json.tool
or, if the JSON is in a file, you can do:
python -m json.tool my_json.json
if the JSON is from an internet source such as ...
What's wrong with foreign keys?
... a foreign key (if I remember correctly). However, to me they seem pretty vital to avoid duplication and subsequent data integrity problems throughout your database.
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How to use a variable to specify column name in ggplot
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If for whatever reason you'd rather not use aes_string, you could change it to (the somewhat more cumbersome):
ggplot( rates.by.groups, aes(x=name, y=rate, colour= get(column),
group=get(column) ) )
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You have already activated rake 0.9.0, but your Gemfile requires rake 0.8.7
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First, check to make sure that rake is mentioned in your Gemfile. If it's not, add it, and specify the version "you already activated".
Then, you'll need to tell bundle to update the rake version it's using for your app:
bundle update rake
It'll update your Gemfile.lock for you.
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