Thread overview
Strange function
Nov 12, 2019
Orfeo
Nov 12, 2019
Adam D. Ruppe
Nov 12, 2019
Orfeo
November 12, 2019
In druntime (core/bitop.d line 302) I found this function

```
/**
 * Tests and resets (sets to 0) the bit.
 */
int btr(size_t* p, size_t bitnum) pure @system;

```



Honestly don't understand: where is the body of the function?

I thought I could find something like that:

```
int btr(size_t* p, size_t bitnum) pure @system {
  // body
}


Thank you





November 12, 2019
On Tuesday, 12 November 2019 at 20:45:11 UTC, Orfeo wrote:
> In druntime (core/bitop.d line 302) I found this function

it is a magic function that the compiler recognizes and outputs a cpu instruction instead of a regular call.

core.bitop has a few of those.

November 12, 2019
On Tuesday, 12 November 2019 at 21:05:35 UTC, Adam D. Ruppe wrote:
> On Tuesday, 12 November 2019 at 20:45:11 UTC, Orfeo wrote:
>> In druntime (core/bitop.d line 302) I found this function
>
> it is a magic function that the compiler recognizes and outputs a cpu instruction instead of a regular call.
>
> core.bitop has a few of those.

Wow! Thank you very much