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How to make the 'cut' command treat same sequental delimiters as one?
... characters to tab. For example: I came here looking for a way to automatically export my display: who am i | tr -s ' ()' '\t' | cut -f5
– Leo
Mar 28 '16 at 23:24
...
Does SQLAlchemy have an equivalent of Django's get_or_create?
...
That's basically the way to do it, there is no shortcut readily available AFAIK.
You could generalize it ofcourse:
def get_or_create(session, model, defaults=None, **kwargs):
instance = session.query(model).filter_by(**kwargs).firs...
git + LaTeX workflow
...ve my work computer and my laptop, and I work on them both. I need to keep all the files synchronized between the two computers, and also would like to keep a revision history. I chose git as my DVCS, and I'm hosting my repository on my server. I'm also using Kile + Okular to do the editing. Kile do...
Is it better to use std::memcpy() or std::copy() in terms to performance?
...y.
I wrote a C++ SHA-2 implementation. In my test, I hash 5 strings using all four SHA-2 versions (224, 256, 384, 512), and I loop 300 times. I measure times using Boost.timer. That 300 loop counter is enough to completely stabilize my results. I ran the test 5 times each, alternating between the m...
How to get the name of enumeration value in Swift?
... on each case to return a string literal. In addition, this works automatically for any enum, even if no raw-value type is specified.
debugPrint(_:) & String(reflecting:) can be used for a fully-qualified name:
debugPrint(city)
// prints "App.City.Melbourne" (or similar, depending on the full ...
Add new field to every document in a MongoDB collection
...field" : 1, "test" : "a" }
EDIT:
In case you want to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents
db.your_collection.update(
{},
{ $set: {"new_field": 1} },
false,
true
)
EDIT:
In the above ...
Missing include “bits/c++config.h” when cross compiling 64 bit program on 32 bit in Ubuntu
...ying to cross compile to a 64 bit target. Based on my research, I have installed the g++-multilib package.
8 Answers
...
Iterating C++ vector from the end to the beginning
...;
i != my_vector.rend(); ++i ) {
}
rbegin()/rend() were especially designed for that purpose. (And yes, incrementing a reverse_interator moves it backward.)
Now, in theory, your method (using begin()/end() & --i) would work, std::vector's iterator being bidirectional, but remember,...
Is there an exponent operator in C#?
...o in most programs, and
it doesn't seem justified to add an
operator when calling Math.Pow() is
simple.
You asked:
Do I have to write a loop or include
another namespace to handle
exponential operations? If so, how do
I handle exponential operations using
non-integers?
Math.Pow supports double p...
How much is the overhead of smart pointers compared to normal pointers in C++?
..._ptr always has memory overhead for reference counter, though it is very small.
std::unique_ptr has time overhead only during constructor (if it has to copy the provided deleter and/or null-initialize the pointer) and during destructor (to destroy the owned object).
std::shared_ptr has time overhe...