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How to save a PNG image server-side, from a base64 data string
...plode(';', $data);
list(, $data) = explode(',', $data);
$data = base64_decode($data);
file_put_contents('/tmp/image.png', $data);
And as a one-liner:
$data = base64_decode(preg_replace('#^data:image/\w+;base64,#i', '', $data));
An efficient method for extracting, decoding, and checking for e...
Safe (bounds-checked) array lookup in Swift, through optional bindings?
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WARNING! Checking arrays this way can be really expensive. The contains method will iterate through all indices thus making this an O(n). A better way is to use the index and count to check the bounds.
– Stefan Vasiljevic
May 7 '...
Calculate distance between 2 GPS coordinates
...y solution:
#include <math.h>
#include "haversine.h"
#define d2r (M_PI / 180.0)
//calculate haversine distance for linear distance
double haversine_km(double lat1, double long1, double lat2, double long2)
{
double dlong = (long2 - long1) * d2r;
double dlat = (lat2 - lat1) * d2r;
...
Purpose of returning by const value? [duplicate]
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In the hypothetical situation where you could perform a potentially expensive non-const operation on an object, returning by const-value prevents you from accidentally calling this operation on a temporary. Imagine that + returned a non-const value, and you could write:
(a + b).expensiv...
Increasing the maximum number of TCP/IP connections in Linux
...local_port_range = 32768 61000
net.ipv4.tcp_fin_timeout = 60
This basically means your system cannot consistently guarantee more than (61000 - 32768) / 60 = 470 sockets per second. If you are not happy with that, you could begin with increasing the port_range. Setting the range to 15000 61000 is...
UITableView is starting with an offset in iOS 7
...ed Aug 22 '13 at 19:05
Mick MacCallum
122k4040 gold badges273273 silver badges274274 bronze badges
answered Aug 22 '13 at 19:02
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How to serialize a lambda?
...le)() -> System.out.println("Serializable!");
And the lambda automagically becomes serializable.
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Why does the C++ STL not provide any “tree” containers?
...we have
std::map (and std::multimap)
std::set (and std::multiset)
Basically the characteristics of these two containers is such that they practically have to be implemented using trees (though this is not actually a requirement).
See also this question:
C tree Implementation
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Regular expression: find spaces (tabs/space) but not newlines
... You'll need to either normalize your strings first (such as by replacing all \u3000 with \u0020), or you'll have to use a character set that includes this codepoint in addition to whatever other whitespace you're targeting, such as [ \t\u3000].
If you're using Perl or PCRE, you have the option of...
Should I pass a shared_ptr by reference? [duplicate]
...mber of bugs arise from improper lifetime management. What's worse conceptually is that it is never clear who owns the objects whose pointers the container stores. The pointers could even be a mix of pointers to dynamic objects, automatic objects, and garbage. Nobody can tell. So the standard soluti...