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Is there a way to instantiate objects from a string holding their class name?
...ce() { return new T; }
typedef std::map<std::string, Base*(*)()> map_type;
map_type map;
map["DerivedA"] = &createInstance<DerivedA>;
map["DerivedB"] = &createInstance<DerivedB>;
And then you can do
return map[some_string]();
Getting a new instance. Another idea is ...
What does `m_` variable prefix mean?
I often see m_ prefix used for variables ( m_World , m_Sprites ,...) in tutorials, examples and other code mainly related to game development.
...
How to write the Fibonacci Sequence?
... now be 1, and b will also be 1, (0 + 1)
and usage:
for index, fibonacci_number in zip(range(10), fib()):
print('{i:3}: {f:3}'.format(i=index, f=fibonacci_number))
prints:
0: 0
1: 1
2: 1
3: 2
4: 3
5: 5
6: 8
7: 13
8: 21
9: 34
10: 55
(For attribution...
Passing a std::array of unknown size to a function
...ctor, as suggested in the comments to the question):
template<std::size_t SIZE>
void mulArray(std::array<int, SIZE>& arr, const int multiplier) {
for(auto& e : arr) {
e *= multiplier;
}
}
Here is a live example.
...
while (1) vs. while(True) — Why is there a difference (in python 2 bytecode)?
...oes.
Here's 2.7:
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL 0 (True)
3 LOAD_CONST 1 (1)
6 COMPARE_OP 2 (==)
9 RETURN_VALUE
>>> dis.dis('True == 1')
1 0 LOAD_GLOBAL ...
When do I use the PHP constant “PHP_EOL”?
When is it a good idea to use PHP_EOL ?
19 Answers
19
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PHP equivalent of .NET/Java's toString()
...
@MarkAmery He gave an answer that implicitly calls the __toString() "Magic Method", but didn't mention that at all. The user asked for an answer that was like the Java toString() method, and in PHP, that's the __toString() function.
– Supuhstar
...
Can Flask have optional URL parameters?
...
Another way is to write
@user.route('/<user_id>', defaults={'username': None})
@user.route('/<user_id>/<username>')
def show(user_id, username):
pass
But I guess that you want to write a single route and mark username as optional? If that's the c...
Programmatically obtain the Android API level of a device?
... obtain API level programatically by the system constant (Build.VERSION.SDK_INT). For example you can run some piece of code which requires newer API in the following way (it will execute if the current device's API level is at least 4)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.DONUT) {
...
What are “connecting characters” in Java identifiers?
...rds.
http://www.fileformat.info/info/unicode/category/Pc/list.htm
U+005F _ LOW LINE
U+203F ‿ UNDERTIE
U+2040 ⁀ CHARACTER TIE
U+2054 ⁔ INVERTED UNDERTIE
U+FE33 ︳ PRESENTATION FORM FOR VERTICAL LOW LINE
U+FE34 ︴ PRESENTATION FORM FOR VERTICAL WAVY LOW LINE
U+FE4D ﹍ DASHED LOW LINE
U+FE4E...