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MIN and MAX in C
... 3rd operand against each other. For example, the result of GENERIC_MAX(my_char1, my_char2) would be an int. To prevent the macro from doing such potentially dangerous type promotions, a final type cast to the intended type was used.
Rationale
We want both parameters to the macro to be of the same...
How to exclude this / current / dot folder from find “type d”
...his particular case (.), golfs better than the mindepth solution (24 vs 26 chars), although this is probably slightly harder to type because of the !.
To exclude other directories, this will golf less well and requires a variable for DRYness:
D="long_name"
find "$D" ! -path "$D" -type d
My decis...
What is the difference between an int and an Integer in Java and C#?
...nt is not an object.
int is one of the few primitives in Java (along with char and some others). I'm not 100% sure, but I'm thinking that the Integer object more or less just has an int property and a whole bunch of methods to interact with that property (like the toString() method for example). So...
How to convert std::string to NSString?
...even fairly straightforward NSString content --- for instance, punctuation characters with a bidirectional encoding. */
– cyrilchampier
Nov 4 '12 at 15:14
...
When should I use perror(“…”) and fprintf(stderr, “…”)?
...
perror(const char *s): prints the string you give it followed by a string that describes the current value of errno.
stderr: it's an output stream used to pipe your own error messages to (defaults to the terminal).
Relevant:
char *stre...
Left-pad printf with spaces
...
If you want the word "Hello" to print in a column that's 40 characters wide, with spaces padding the left, use the following.
char *ptr = "Hello";
printf("%40s\n", ptr);
That will give you 35 spaces, then the word "Hello". This is how you format stuff when you know how wide you wa...
What and where are the stack and heap?
...ate a lot of data.
Responsible for memory leaks.
Example:
int foo()
{
char *pBuffer; //<--nothing allocated yet (excluding the pointer itself, which is allocated here on the stack).
bool b = true; // Allocated on the stack.
if(b)
{
//Create 500 bytes on the stack
char buffer[50...
differentiate null=True, blank=True in django
...o need your database to allow NULL values for that field. The exception is CharFields and TextFields, which in Django are never saved as NULL. Blank values are stored in the DB as an empty string ('').
A few examples:
models.DateTimeField(blank=True) # raises IntegrityError if blank
models.DateTi...
Error handling in C code
...rs into something human readable. Can be simple. Just error-enum in, const char* out.
I know this idea makes multithreaded use a bit difficult, but it would be nice if application programmer can set an global error-callback. That way they will be able to put a breakpoint into the callback during bug...
Why do we need argc while there is always a null at the end of argv?
...
...Which is a shame, in a way. If we had int main(char *argv[], int argc, ...), then some programs could just omit the argc because they do not need it. Opposite (needing argc but not argv) is probably never useful in a real program.
– hyde
...