如果这样写：

#include "say.h" 
#include <Foundation/Foundation.h> 
 
int main(void)  
{ 
        id speaker; 
        NSString *name = @"GNUstep !"; 
        NSAutoreleasePool *pool; 
        NSArray           *outArray; 
        NSArray                     *array2; 
         
        array2 = [NSMutableArray arrayWithCapacity:20]; 
         
        pool = [NSAutoreleasePool new]; 
        speaker = [[Say alloc] init]; 
        outArray = [NSArray arrayWithObjects: @"Msg1", @"Msg2", @"Msg3", @"Msg4", nil]; 
        //printf("%@\n", [outArray objectAtIndex: 0]);      //GNUstep下只输出了@ 
        //GSPrintf(stdout, "%@", [outArray objectAtIndex: 1]);  // GNUstep下崩溃 
        NSLog(@"%@\n", [outArray objectAtIndex: 2]);                        // GNUStep下ok 
         
        [speaker sayHello]; 
        [speaker sayHelloTo: name]; 
         
        RELEASE(speaker); 
        RELEASE(pool); 
         
        #ifdef DEBUG 
            NSLog(@"%@\n", @"Debug Now"); 
        #endif 
         
        return 0; 
} 

array2 就不受内存池管控，执行时会报错：

$ ./obj/HelloWorld.exe

2013-03-15 15:20:57.015 HelloWorld[5372] autorelease called without pool for ob

ect (0x3eb2f8) of class GSMutableArray in thread <NSThread: 0x520878>

把 array2 = [NSMutableArray arrayWithCapacity:20]; 放置到 pool = [NSAutoreleasePool new]; 之后，就没有问题了。