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How should one use std::optional?
...nt(std::string s); //return nullptr if fail
This requires dynamic memory allocation, worrying about ownership, etc. - always prefer one of the other two signatures above.
Another example:
class Contact
{
std::optional<std::string> home_phone;
std::optional<std::string> work...
Get the first element of an array
... a array "copy" is needed:
array_shift(array_slice($array, 0, 1));
With PHP 5.4+ (but might cause an index error if empty):
array_values($array)[0];
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Which is more efficient, a for-each loop, or an iterator?
...te a new Iterator when .iterator() is called, however they can be accessed allocation-free using the C-style loop. This can be important in certain high-performance environments where one is trying to avoid (a) hitting the allocator or (b) garbage collections.
– Dan
...
Traits vs. interfaces
I've been trying to study up on PHP lately, and I find myself getting hung up on traits. I understand the concept of horizontal code reuse and not wanting to necessarily inherit from an abstract class. What I don't understand is: What is the crucial difference between using traits versus interfaces?...
How to establish a connection pool in JDBC?
...re using same object's to perform any action on Object-Data] & memory [allocating and de-allocating many objects creates a significant memory management overhead].
Object clean-up is not required as we are using same Object, reducing the Garbage collection load.
« Pooling [ Object pool, Strin...
Warning “Do not Access Superglobal $_POST Array Directly” on Netbeans 7.4 for PHP
I've got this message warning on Netbeans 7.4 for PHP while I'm using $_POST , $_GET , $_SERVER , ....
5 Answers
...
tinyxml XML解析库下载（tinyxml2.h 和 tinyxml2.cpp） - 源码下载 - 清泛...
...>
# include <cstdarg>
#endif
/*
TODO: intern strings instead of allocation.
*/
/*
gcc:
g++ -Wall -DDEBUG tinyxml2.cpp xmltest.cpp -o gccxmltest.exe
Formatting, Artistic Style:
AStyle.exe --style=1tbs --indent-switches --break-closing-brackets --indent-preproce...
How to find out if you're using HTTPS without $_SERVER['HTTPS']
...RVER['SERVER_PORT'] == 443;
}
The code is compatible with IIS.
From the PHP.net documentation and user comments :
1) Set to a non-empty value if the script was queried through the HTTPS protocol.
2) Note that when using ISAPI with IIS, the value will be "off" if the request was not made ...
PHP regular expressions: No ending delimiter '^' found in
...
PHP regex strings need delimiters. Try:
$numpattern="/^([0-9]+)$/";
Also, note that you have a lower case o, not a zero. In addition, if you're just validating, you don't need the capturing group, and can simplify the rege...
jQuery pass more parameters into callback
.../ an object / whatever extra params you wish to pass.
$.post("someurl.php", someData, doSomething(extraStuff), "json");
};
What is happening?
In the last line, doSomething(extraStuff) is invoked and the result of that invocation is a function pointer.
Because extraStuff is passed as an argu...