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dynamic_cast and static_cast in C++
...
Here's a rundown on static_cast<> and dynamic_cast<> specifically as they pertain to pointers. This is just a 101-level rundown, it does not cover all the intricacies.
static_cast< Type* >(ptr)
This takes the pointer in ptr and tries to safely cast it to a pointer of type Type...
Explain the encapsulated anonymous function syntax
...ression:
(function foo() {
alert(2 + 2);
}());
The Parentheses (formally called the Grouping Operator) can surround only expressions, and a function expression is evaluated.
The two grammar productions can be ambiguous, and they can look exactly the same, for example:
function foo () {} // ...
When should you not use virtual destructors?
...o not declare a virtual destructor for a class? When should you specifically avoid writing one?
12 Answers
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Which comment style should I use in batch files?
...re expanded. Suppose you have (wrongly) set TARGET=C:\Program Files (x86)\"foo.exe", and inside a DO(..) expression you have :: echo %TARGET% you will get an error because the (x86) gets expanded before the whole expression gets evaluated, leading to an invalid DO(..) expression and very inexplicabl...
What is attr_accessor in Ruby?
...d. What it does is create more methods for you.
So this code here:
class Foo
attr_accessor :bar
end
is equivalent to this code:
class Foo
def bar
@bar
end
def bar=( new_value )
@bar = new_value
end
end
You can write this sort of method yourself in Ruby:
class Module
def v...
How do I convert a Ruby class name to a underscore-delimited symbol?
How can I programmatically turn a class name, FooBar , into a symbol, :foo_bar ? e.g. something like this, but that handles camel case properly?
...
Get keys from HashMap in Java
...HashMap contains more than one key. You can use keySet() to get the set of all keys.
team1.put("foo", 1);
team1.put("bar", 2);
will store 1 with key "foo" and 2 with key "bar". To iterate over all the keys:
for ( String key : team1.keySet() ) {
System.out.println( key );
}
will print "foo"...
How do you add Boost libraries in CMakeLists.txt?
... it can also help to add this to your cmake file: ADD_DEFINITIONS( -DBOOST_ALL_NO_LIB ) otherwise you may run into stackoverflow.com/questions/28887680/…
– Stéphane
Jul 22 '15 at 16:08
...
How do I append one string to another in Python?
...ugh memory to resize the string, the original
string object at *pv is deallocated, *pv is set to NULL, an "out of
memory" exception is set, and -1 is returned. Else (on success) 0 is
returned, and the value in *pv may or may not be the same as on input.
As always, an extra byte is alloc...
What is the purpose of the single underscore “_” variable in Python?
...cate that part
of a function result is being deliberately ignored (Conceptually, it is being discarded.), as in code like:
label, has_label, _ = text.partition(':').
As part of a function definition (using either def or lambda), where
the signature is fixed (e.g. by a callback or parent class API), ...