Wierd pointer construct

Question

I've run across this pointer construction and I'm not familiar with it. Can someone explain please.

void Test_GPS::begin(uint16_t baud)
{
    gpspointer->begin(baud);
}

What does the -> do? And it seems recursive.

What is the type of `gpspointer`? This isn't quite recursive. Recursive would be `this->begin(baud)`. This is just calling the `begin` method on some other pointer for whatever reason. — Cory Kramer, Jun 23 '15 at 11:50
Barring operator overloading, `a->b` is a shortand for `(*a).b`. — Matteo Italia, Jun 23 '15 at 11:50
It's described in any elementary introduction to pointers in both C and C++, so "wierd" is an exaggeration. — molbdnilo, Jun 23 '15 at 11:56
This question would be best answered by reading a [good C++ book](http://stackoverflow.com/q/388242/1782465). — Angew is no longer proud of SO, Jun 23 '15 at 12:04

score 2 · Answer 1 · answered Jun 23 '15 at 11:55

2

You should really get a C/C++ Book and learn your language, before you start programming.

-> is the dereferencing operator for Pointers. When you have a pointer gpspointer the expression (*gpspointer) returns the object gpspointer points to. (*gpspointer).begin(baud) is the same as gpspointer->begin(baud). It just increases readability.

Your code will recurse only if gpspointer=this.

answered Jun 23 '15 at 11:55

ikrabbe

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Thank-you ikrabbe. Makes sense now. I hadn't seen that representation before. My K&R book doesn't mention it. – Trillian86 Jun 23 '15 at 12:04
3

K&R is about ANSI C, not C++ and I doubt that K&R does not mention the `->` operator. Hmm It's about 25 years ago I read my K&R, so maybe I'm wrong on this. – ikrabbe Jun 23 '15 at 12:05
@Trillian86 The index says it's on pages 131 and 201 in the 2nd edition. – molbdnilo Jun 23 '15 at 12:34

Wierd pointer construct

1 Answers1