Colon operator in a variable declaration statement inside struct [duplicate]

This question already开发者_如何转开发 has answers here: Closed 11 years ago.

Possible Duplicate:

What does 'unsigned temp:3' means

struct sample{
    int x    :2;
    char y   :4;
};

What does the colon operator do in the above code?

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It is used to specify bit fields. The size of the field is given in bits. The layout is compiler-specific.