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When is std::weak_ptr useful?
...ts and it points to nullptr when the object pointed is deleted/not pointed by any other pointers anymore?
– user1434698
Aug 19 '12 at 23:16
30
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Image comparison - fast algorithm
...appropriate bucket. When we're done tallying, we divide each bucket total by the number of pixels in the entire image to get a normalized histogram for the green channel.
For the texture direction histogram, we started by performing edge detection on the image. Each edge point has a normal vector...
What is the difference between POST and GET? [duplicate]
... web applications. One reason for this is that GET may be used arbitrarily by robots or crawlers, which should not need to consider the side effects that a request should cause.
and
POST submits data to be processed (e.g., from an HTML form) to the identified resource. The data is included in...
What's the “big idea” behind compojure routes?
... the notion of "routes". These are actually implemented at a deeper level by the Clout library (a spinoff of the Compojure project -- many things were moved to separate libraries at the 0.3.x -> 0.4.x transition). A route is defined by (1) an HTTP method (GET, PUT, HEAD...), (2) a URI pattern (...
How can you use an object's property in a double-quoted string?
... you enclose a variable name in a double-quoted string it will be replaced by that variable's value:
$foo = 2
"$foo"
becomes
"2"
If you don't want that you have to use single quotes:
$foo = 2
'$foo'
However, if you want to access properties, or use indexes on variables in a double-quoted st...
What is the http-header “X-XSS-Protection”?
...
X-XSS-Protection is a HTTP header understood by Internet Explorer 8 (and newer versions).
This header lets domains toggle on and off the "XSS Filter" of IE8, which prevents some categories of XSS attacks.
IE8 has the filter activated by default, but servers can switch i...
Circle line-segment collision detection algorithm?
...Vector from center sphere to ray start )
Then the intersection is found by..
Plugging:
P = E + t * d
This is a parametric equation:
Px = Ex + tdx
Py = Ey + tdy
into
(x - h)2 + (y - k)2 = r2
(h,k) = center of circle.
Note: We've simplified the problem to 2D here, the solution we get applies ...
Efficiently convert rows to columns in sql server
...(ColumnName)
from yourtable
group by ColumnName, id
order by id
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set @query = N'SELECT ' + @cols + N' from
(
selec...
Passing a 2D array to a C++ function
...
Fixed Size
1. Pass by reference
template <size_t rows, size_t cols>
void process_2d_array_template(int (&array)[rows][cols])
{
std::cout << __func__ << std::endl;
for (size_t i = 0; i < rows; ++i)
{
...
Can git undo a checkout of unstaged files
... yet added (staged), it is purely "private".
Meaning it cannot be restored by GIT if overwritten with the index or the HEAD version (unless you have a copy of your current work somewhere).
A "private" content is one only visible in your current directory, but not registered in any way in Git.
Note: ...