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What are Aggregates and PODs and how/why are they special?
...d only in PODs then you must first read the definition, implications, and examples of aggregates and then you may jump to PODs but I would still recommend reading the first part in its entirety. The notion of aggregates is essential for defining PODs. If you find any errors (even minor, including gr...
Remove empty strings from a list of strings
...ythonic way:
>>> strings = ["first", "", "second"]
>>> [x for x in strings if x]
['first', 'second']
If the list must be modified in-place, because there are other references which must see the updated data, then use a slice assignment:
strings[:] = [x for x in strings if x]
...
Why aren't python nested functions called closures?
... access to a local variable from an enclosing scope that has finished its execution.
def make_printer(msg):
def printer():
print msg
return printer
printer = make_printer('Foo!')
printer()
When make_printer is called, a new frame is put on the stack with the compiled code for the...
Elegant way to combine multiple collections of elements?
...rary number of collections, each containing objects of the same type (for example, List<int> foo and List<int> bar ). If these collections were themselves in a collection (e.g., of type List<List<int>> , I could use SelectMany to combine them all into one collection.
...
jQuery deferreds and promises - .then() vs .done()
... information on pipe().
success() and error() are only available on the jqXHR object returned by a call to ajax(). They are simple aliases for done() and fail() respectively:
jqXHR.done === jqXHR.success
jqXHR.fail === jqXHR.error
Also, done() is not limited to a single callback and will filter ...
In R, how to get an object's name after it is sent to a function?
...
The old deparse-substitute trick:
a<-data.frame(x=1:10,y=1:10)
test<-function(z){
mean.x<-mean(z$x)
nm <-deparse(substitute(z))
print(nm)
return(mean.x)}
test(a)
#[1] "a" ... this is the side-effect of the print() call
# ... you could have...
What is 'Currying'?
...o curried functions in several articles and blogs but I can't find a good explanation (or at least one that makes sense!)
1...
How do I put two increment statements in a C++ 'for' loop?
... operator at all. I checked that in GCC as follows:
int i=0;
int a=5;
int x=0;
for(i; i<5; x=i++,a++){
printf("i=%d a=%d x=%d\n",i,a,x);
}
I was expecting x to pick up the original value of a, so it should have displayed 5,6,7.. for x. What I got was this
i=0 a=5 x=0
i=1 a=6 x=0
i=2 a=7 ...
How to determine if a point is in a 2D triangle? [closed]
...ou started:
float sign (fPoint p1, fPoint p2, fPoint p3)
{
return (p1.x - p3.x) * (p2.y - p3.y) - (p2.x - p3.x) * (p1.y - p3.y);
}
bool PointInTriangle (fPoint pt, fPoint v1, fPoint v2, fPoint v3)
{
float d1, d2, d3;
bool has_neg, has_pos;
d1 = sign(pt, v1, v2);
d2 = sign(pt, ...
How to count certain elements in array?
... just to compare it to a value is not elegant.
– Felix Kling
May 25 '11 at 8:33
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