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#pragma pack effect
...essing variables that are not aligned properly. For example, given 4-byte integers and the following struct:
struct Test
{
char AA;
int BB;
char CC;
};
The compiler could choose to lay the struct out in memory like this:
| 1 | 2 | 3 | 4 |
| AA(1) | pad..................
Forward declaration of nested types/classes in C++
...
class IDontControl
{
class Nested
{
Nested(int i);
};
};
I needed a forward reference like:
class IDontControl::Nested; // But this doesn't work.
My workaround was:
class IDontControl_Nested; // Forward reference to distinct name.
Later when I could use th...
How to handle back button in activity
... // your code.
}
older than API 5
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
// your code
return true;
}
return super.onKeyDown(keyCode, event);
}
...
How to break out or exit a method in Java?
...em.exit(0);
Java language provides three jump statemnts that allow you to interrupt the normal flow of program.
These include break , continue ,return ,labelled break statement
for e.g
import java.util.Scanner;
class demo
{
public static void main(String args[])
{
outerLo...
Is there a standard sign function (signum, sgn) in C/C++?
...one has posted the type-safe C++ version yet:
template <typename T> int sgn(T val) {
return (T(0) < val) - (val < T(0));
}
Benefits:
Actually implements signum (-1, 0, or 1). Implementations here using copysign only return -1 or 1, which is not signum. Also, some implementations...
Using sphinx with Markdown instead of RST
...er from scratch:
You could cheat and write a "parser" that uses Pandoc to convert markdown to RST and pass that to the RST parser :-).
You can use an existing markdown->XML parser and transform the result (using XSLT?) to the docutils schema.
You could take some existing python markdown parser...
How can I multiply and divide using only bit shifting and adding?
...ion)
(_2 means base 2)
As you can see, multiplication can be decomposed into adding and shifting and back again. This is also why multiplication takes longer than bit shifts or adding - it's O(n^2) rather than O(n) in the number of bits. Real computer systems (as opposed to theoretical computer s...
Group by multiple columns in dplyr, using string vector input
...orm(100)
)
# Columns you want to group by
grp_cols <- names(df)[-3]
# Convert character vector to list of symbols
dots <- lapply(grp_cols, as.symbol)
# Perform frequency counts
df %>%
group_by_(.dots=dots) %>%
summarise(n = n())
output:
Source: local data frame [9 x 3]
Grou...
Does Typescript support the ?. operator? (And, what's it called?)
..., including the type conversions such as...
var n: number = +myString; // convert to number
var b: bool = !!myString; // convert to bool
Manual Solution
But back to the question. I have an obtuse example of how you can do a similar thing in JavaScript (and therefore TypeScript) although I'm defi...
How to suppress scientific notation when printing float values?
...o say, "you manage the display of precision yourself." The actual (Python internal) precision isn't changed, as is often done in other languages.
– JS.
Aug 22 '12 at 20:42
ad...