What does the : do in a struct declaration after a member

Question

In:

struct foo {
  unsigned bar : 2;
};

What does the ': 2' do?

It helps you to avoid ugly padding in some cases :) – Tim Post Nov 04 '09 at 17:15 — Tim Post, Nov 04 '09 at 17:15

score 15 · Accepted Answer · answered Nov 04 '09 at 17:10

15

It declares a bit field. The number specifies the size of that member in bits.

answered Nov 04 '09 at 17:10

Mehrdad Afshari

1 Answers1