Test code for http://bou.io/ConstantStringsInObjC.html

NSConstantString_test.m

//
//  clang -framework Foundation NSConstantString_test.m; ./a.out; rm ./a.out
//

#import <Foundation/Foundation.h>

#define PrintObjectInfo(obj) \
  do{id _obj = ( obj );\
    printf("%-61s %-20s %-16p %ld\n", #obj" :", [NSStringFromClass([_obj class]) UTF8String], _obj, [_obj retainCount]);\
}while(0);

int main(int argc, const char * argv[])
{
    NSString *a = @"a";
    PrintObjectInfo(a);
    PrintObjectInfo(@"a");
    PrintObjectInfo(@"some string");
    PrintObjectInfo([@"a" copy]);
    PrintObjectInfo([@"a" mutableCopy]);
    PrintObjectInfo([[@"a" mutableCopy] copy]);
    PrintObjectInfo([[@"b" mutableCopy] copy]);
    PrintObjectInfo([[@"ab" mutableCopy] copy]);
    PrintObjectInfo([[@"$" mutableCopy] copy]);
    PrintObjectInfo([[@"/" mutableCopy] copy]);
    PrintObjectInfo([[@"€" mutableCopy] copy]);
    PrintObjectInfo([[@"§" mutableCopy] copy]);
    PrintObjectInfo([[[@"a" mutableCopy] copy] retain]);
    PrintObjectInfo(([NSString stringWithFormat:@"%s","a"]));
    PrintObjectInfo([@"/some/path/to/a" lastPathComponent]);
    PrintObjectInfo([[@"/some/path/to/a" lastPathComponent] copy]);
    PrintObjectInfo([[[@"/some/path/to/a" lastPathComponent] mutableCopy] copy]);
    PrintObjectInfo([[[@"path/a" lastPathComponent] mutableCopy] copy]);
    
    return 0;
}