what is an opaque_type?

[=?gb2312?B?wNbA1rTzzOzKpg==?=]

I see a declaraion in a open source software: "opaque_type( Doc );".
Then what is an opaque_type? Is it a macro?

[Kai-Uwe Bux]

????? wrote:

I see a declaraion in a open source software: "opaque_type( Doc );".
Then what is an opaque_type? Is it a macro?

Who knows: the identifier "opaque_type" is not defined by the C++ language.
Without seeing the code you have before you, nobody can tell.
Best

Kai-Uwe Bux

[Greg]

��大天师 wrote:

I see a declaraion in a open source software: "opaque_type( Doc );".
Then what is an opaque_type? Is it a macro?

In C and C++ an opaque type is a pointer to an incomplete type that is
never defined.

For information on the uses and benefits of opaque types see:

http://developer.apple.com/documenta...pts/index.html

Greg

[Greg]

��大天师 wrote:

I see a declaraion in a open source software: "opaque_type( Doc );".
Then what is an opaque_type? Is it a macro?

In C and C++ an opaque type is a pointer to an incomplete type that is
never defined.

For information on the uses and benefits of opaque types see:
http://tinyurl.com/2n3mcz

Greg

[Roland Pibinger]

On 22 Jan 2007 23:51:23 -0800, "Greg" wrote:

>=E4=B9=90=E4=B9=90=E5=A4=A7=E5=A4=A9=E5=B8=88 wrote:

>I see a declaraion in a open source software: "opaque_type( Doc );".
Then what is an opaque_type? Is it a macro?

In C and C++ an opaque type is a pointer to an incomplete type

I'd agree with that definition. Sometimes also void* is described as
opaque type which is IMO misleading and should be avoided.

>that is never defined.

.... that is not defined in a header file accessible to the user. It
needs to be defined somewhere.

Best regards,
Roland Pibinger