• Orfeo (14/14) Nov 12 2019 In druntime (core/bitop.d line 302) I found this function
• Adam D. Ruppe (4/5) Nov 12 2019 it is a magic function that the compiler recognizes and outputs a
• Orfeo (2/7) Nov 12 2019 Wow! Thank you very much

Orfeo <dlang orfeo.fastmail.com> writes:

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

Adam D. Ruppe <destructionator gmail.com> writes:

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.

Orfeo <dlang orfeo.fastmail.com> writes:

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