[swift-users] Generic math macros on Linux

[Dmitri Gribenko]

On Wed, Jan 27, 2016 at 11:23 PM, Timothy Chagnon via swift-users
<swift-users at swift.org> wrote:
> Hi folks,
>
> I ran into this issue (or at least surprise) trying to compile some code
> that uses math.h functions on both OSX and Linux.  Here's an example:
>
> #if os(Linux)
>   import Glibc
> #else
>   import Darwin
> #endif
>
> let x = Float(1.2345)
> let y = sin(x)
> print(y)
>
> Compiles and runs fine on OSX, but fails with the following error on Linux:
> MathTest.swift:8:13: error: cannot convert value of type 'Float' to expected
> argument type 'Double'
>
> I think I tracked this down to the fact that Darwin includes the additional
> tgmath style macros that provide the overloaded sin(x: Float) -> Float swift
> function. Glibc only includes plain math.h functions:
> double sin(double x);
> float sinf(float x);
>
> I can, of course, just use the explicit *f math.h functions on both
> platforms.  But I'm curious if this is a bug I should file or if this is
> intentional to not have overloaded math functions in Swift.  I couldn't find
> much mention of it in the bug tracker.

Yes, Glibc module is lacking an overlay for tgmath.  Please file a bug.

Dmitri

-- 
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/