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What are the advantages of using nullptr?
...pecified by C standard useless in many C++ expressions. For example:
std::string * str = NULL; //Case 1
void (A::*ptrFunc) () = &A::doSomething;
if (ptrFunc == NULL) {} //Case 2
If NULL was defined as (void *)0, neither of above expressions would work.
Case 1: Will not com...
Regular expression to allow spaces between words
...f the following cases that one would not usually mean to match:
An empty string, "".
A string comprised entirely of spaces, " ".
A string that leads and / or trails with spaces, " Hello World ".
A string that contains multiple spaces in between words, "Hello World".
Origi...
What is your favorite C programming trick? [closed]
...re you can write "str[]" as the last member of a struct). you could make a string "object" like this:
struct X {
int len;
char str[1];
};
int n = strlen("hello world");
struct X *string = malloc(sizeof(struct X) + n);
strcpy(string->str, "hello world");
string->len = n;
here, we've...
Why can Java Collections not directly store Primitives types?
...tion of primitives. Even in the few cases where I might have wanted to the extra time and space costs of using the reference objects has been negligible. In particular I find that many people think they want Map<int,T>, forgetting that an array will do that trick very nicely.
...
What is the difference between “px”, “dip”, “dp” and “sp”?
...tual screen sizes into four
generalized sizes: small, normal, large, and extra-large.
Screen density
The number of pixels within a physical area of the
screen; usually referred to as dpi (dots per inch). For example, a
"low" density screen has fewer pixels within a given physical area,...
Variable declaration placement in C
...ation and initialization of a C++ local object then you pay the cost of an extra constructor for nothing. If the no-arg constructor does not exist then again you are not even allowed to separate both!
C99 starts to move C in this same direction.
If you are worried of not finding where local varia...
How many characters can a Java String have?
... to a million digits. I thought about using Java's functions for reversing Strings, but would they allow for a String to be this long?
...
Use of #pragma in C
...etween members) in MSVC:
#pragma pack(push, 1)
struct PackedStructure
{
char a;
int b;
short c;
};
#pragma pack(pop)
// sizeof(PackedStructure) == 7
Here's how you'd do the same thing in GCC:
struct PackedStructure __attribute__((__packed__))
{
char a;
int b;
short c;
};
// sizeof(Pa...
How to access session variables from any class in ASP.NET?
...}
// **** add your session properties here, e.g like this:
public string Property1 { get; set; }
public DateTime MyDate { get; set; }
public int LoginId { get; set; }
}
This class stores one instance of itself in the ASP.NET session and allows you to access your session properties...
Extract filename and extension in Bash
... would greedily remove the longest match to the . and you'd have the empty string.
(You can work around that with a temporary variable:
FULL_FILENAME=$FILENAME
FILENAME=${FULL_FILENAME##*/}
echo ${FILENAME%%.*}
)
This site explains more.
${variable%pattern}
Trim the shortest match from th...