Encoding CGPoint struct with NSCoder

How do you encode and decode a CGPoint struct using NSCoder?

From stackoverflow

• CGPoints and NSPoints are both structures composed of two CGFloat values, so you can freely pass them around as each other. The quick and dirty way would be:

  NSCoder *myNSCoder;
  CGPoint myPoint;
  [myNSCoder encodePoint:*(NSPoint *)myPoint];
  

  This will usually work, but it technically breaks the C99 strict aliasing rules. If you want to be 100% compatible with the standard, you'll have to do something like:

  typedef union
  {
    CGPoint cgPoint;
    NSPoint nsPoint;
  } CGNSPoint;
  
  CGNSPoint cgnsPoint = { .cgPoint = myPoint };
  [myNSCoder encodePoint:cgnsPoint.nsPoint];
  

  Ahruman : However, if you’re building for the 64-bit runtime, or have NS_BUILD_32_LIKE_64 defined to 1, NSPoint and CGPoint are typedefed to the same struct, so no casting or union shenanigans are required.

  Peter Hosey : Furthermore, Foundation provides two inline functions named NSPoint{To,From}CGPoint. No need for pointer casting or a union.

• To encode:

  CGPoint point = /* point from somewhere */
  NSValue *pointValue = [NSValue value:&point withObjCType:@encode(CGPoint)];
  [coder encodeObject:pointValue forKey:@"point"];
  

  To decode:

  NSValue *decodedValue = [decoder decodeObjectForKey:@"point"];
  CGPoint point;
  [decodedValue getValue:&point];
  

  Quinn Taylor : +1 This seems like a much better, less hackish general-purpose solution.