Example.mm

#import <Foundation/Foundation.h>
#import "to_object.h"

int main (int argc, const char * argv[]) {
  NSAutoreleasePool *pool = [NSAutoreleasePool new];
  
  const char *str = "wut";
  id o = $<const char *>(str);
  
  NSLog(@"char: %s, string: %@, of class: %@", str, o, [o class]);
  // => char: wut, string: wut, of class: NSCFString
  
  [pool drain];
}

to_object.h

#import <Foundation/Foundation.h>

template <typename T> id $(T v);

to_object.mm

#import <objc/message.h>
#import <string>
#import <map>
#import <typeinfo>

template <typename T> id $(T v) {
  std::map<std::string,NSString *> ops;
  
  ops[typeid(int).name()] = @"NSNumber.numberWithInt:";
  ops[typeid(float).name()] = @"NSNumber.numberWithFloat:";
  ops[typeid(double).name()] = @"NSNumber.numberWithDouble:";
  ops[typeid(const char *).name()] = @"NSString.stringWithUTF8String:";
  ops[typeid(CGPoint).name()] = @"NSValue.valueWithPoint:";
  ops[typeid(CGRect).name()] = @"NSValue.valueWithRect:";
  ops[typeid(CGSize).name()] = @"NSValue.valueWithSize:";
  ops[typeid(void *).name()] = @"NSValue.valueWithPointer:";
  
  NSArray *components = [ops[typeid(v).name()] componentsSeparatedByString:@"."];
  
  Class klass = NSClassFromString([components objectAtIndex:0]);
  SEL sel = NSSelectorFromString([components objectAtIndex:1]);
  
  return objc_msgSend(klass,sel,v);
}