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Object-orientation in C
..., you use function pointers, and optionally function pointer tables, also known as virtual tables or vtables:
struct base;
struct base_vtable
{
void (*dance)(struct base *);
void (*jump)(struct base *, int how_high);
};
struct base
{
struct base_vtable *vtable;
/* base members */
}...
How can I extract embedded fonts from a PDF as valid font files?
...r example by using XPDF's pdftops (on Windows: pdftops.exe helper program.
Now fonts will be embedded in .pfa (PostScript) format + you can extract them using a text editor.
You may need to convert the .pfa (ASCII) to a .pfb (binary) file using the t1utils and pfa2pfb.
In PDFs there are never .pfm o...
Loop through an array in JavaScript
...e this:
var x = [1,2,3,4].map( function(item) {return item * 10;});
And now x is [10,20,30,40].
You don't have to write the function inline. It could be a separate function.
var item_processor = function(item) {
// Do something complicated to an item
}
new_list = my_list.map(item_process...
SQLAlchemy: What's the difference between flush() and commit()?
... # been flushed yet.
s2.flush() # Now, Foo('B') is in the same state as
# Foo('A') was above.
print 3, s2.query(Foo).all()
s2.rollback() # Foo('B') has not been committed, and rolling
...
@property retain, assign, copy, nonatomic in Objective-C
...mic vs. atomic
- "atomic" is the default. Always use "nonatomic". I don't know why, but the book I read said there is "rarely a reason" to use "atomic". (BTW: The book I read is the BNR "iOS Programming" book.)
readwrite vs. readonly
- "readwrite" is the default. When you @synthesize, both a getter...
What is the proper REST response code for a valid request but an empty data?
... this unless you're writing your own server from scratch. Edit: Newer RFCs now allow for 400 to be used for semantically invalid requests.
Wikipedia's description of the HTTP status codes are particularly helpful.
You can also see the definitions in the HTTP/1.1 RFC2616 document at www.w3.org
...
What is the behavior difference between return-path, reply-to and from?
...olstuff-threadId=123@mymailinglist.com>
This is a very simple body.
Now, let's say you are going to send it from a mailing list, that implements VERP (or some other bounce tracking mechanism that uses a different return-path). Lets say it will have a return-path of coolstuff-you=yourcompany....
Generic method multiple (OR) type constraint
...to use one function. Ah well, thanks a lot! Just out of curiosity, do you know if there is a specific reason this isn't possible? (has it been left out of the language deliberately?)
– Mansfield
May 31 '12 at 12:55
...
Why does the C# compiler not fault code where a static method calls an instance method?
...w answer (and this entire question) has mostly only historical interest by now!
(Pre C# 7.3:)
For some reason, overload resolution always finds the best match before checking for static versus non-static. Please try this code with all static types:
class SillyStuff
{
static void SameName(obje...
How does the compilation/linking process work?
... output of the preprocessor. The compiler parses the pure C++ source code (now without any preprocessor directives) and converts it into assembly code. Then invokes underlying back-end(assembler in toolchain) that assembles that code into machine code producing actual binary file in some format(ELF,...