On 17 Mar 2018, at 18:06, amon <[email protected]> wrote:
>
> Just noticed this while researching... it does not appear to be
> possible to create an NSHost object that is *not* autoreleased.
> Is this true or did I miss something in the docs?
As Fred pointed out earlier, whether you create autoreleased instances doesn’t
matter. You can simply write:
NSHost *host;
@autoreleasepool
{
host = [[NSHost hostWithAddress: someAddress] retain];
}
And now you will have a non-autoreleased instance and all temporary objects
constructed by the NSHost class will be destroyed (unless otherwise
referenced). In ARC mode, you can simply write:
NSHost *host;
@autoreleasepool
{
host = [[NSHost hostWithAddress: someAddress] retain];
}
If you want to simplify this, then you can wrap it up in a function that takes
a block:
static inline id get_retained(id(^block)())
{
@autoreleasepool
{
return block();
}
}
Which you can then use as follows:
NSHost *host = get_retained(^() { return [NSHost currentHost]; });
Or, in Objective-C++ you can do it in a more typesafe way using templates:
#import <Foundation/Foundation.h>
template<typename T>
auto get_retained(T block) -> decltype(block())
{
@autoreleasepool
{
return block();
}
}
Which you can then use in exactly the same way, or using C++ lambdas (which
have slightly less horrible syntax):
NSHost *host = get_retained([]{ return [NSHost currentHost]; });
David
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