What's the usual way to store c-structures in an NSArray
? Advantages, disadvantages, memory handling?
Notably, what's the difference between valueWithBytes
and valueWithPointer
-- raised by justin and catfish below.
Here's a link to Apple's discussion of valueWithBytes:objCType:
for future readers...
For some lateral thinking and looking more at performance, Evgen has raised the issue of using STL::vector
in C++.
(That raises an interesting issue: is there a fast c library, not unlike STL::vector
but much much lighter, that allows for the minimal "tidy handling of arrays" ...?)
So the original question...
For example:
typedef struct _Megapoint {
float w,x,y,z;
} Megapoint;
So: what's the normal, best, idiomatic way to store one's own structure like that in an NSArray
, and how do you handle memory in that idiom?
Please note that I am specifically looking for the usual idiom to store structs. Of course, one could avoid the issue by making a new little class. However I want to know how the usual idiom for actually putting structs in an array, thanks.
BTW here's the NSData approach which is perhaps? not best...
Megapoint p;
NSArray *a = [NSArray arrayWithObjects:
[NSData dataWithBytes:&p length:sizeof(Megapoint)],
[NSData dataWithBytes:&p length:sizeof(Megapoint)],
[NSData dataWithBytes:&p length:sizeof(Megapoint)],
nil];
BTW as a point of reference and thanks to Jarret Hardie, here's how to store CGPoints
and similar in an NSArray
:
NSArray *points = [NSArray arrayWithObjects:
[NSValue valueWithCGPoint:CGPointMake(6.9, 6.9)],
[NSValue valueWithCGPoint:CGPointMake(6.9, 6.9)],
nil];
(see How can I add CGPoint objects to an NSArray the easy way?)
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