[gdal-dev] Hard coded Pi constants

[Jeff McKenna]

Hello,

Be careful, as many GDAL package maintainers, including myself, run 
older Visual Studio versions on Windows.  Declaring this constant is 
done in several software projects.  It may be considered "ugly", but it 
sure works.

-jeff



On 2016-03-03 1:55 PM, Tanuj Kumar wrote:
> This is with regard to the bug listed on
> https://trac.osgeo.org/gdal/ticket/6388
>
> The fix is to remove the hard coded pi constants, but apparently, using
> M_PI from math.h as it is breaks compilation on Visual Studio
> http://stackoverflow.com/questions/26065359/m-pi-flagged-as-undeclared-identifier
> (I haven't checked it yet myself; that would need me to switch to
> windows, and I'm on linux right now)
>
> However, we could also declare #define _USE_MATH_CONSTANTS, and then use
> M_PI without declaring it(And not just M_PI, all the other math
> constants listed on https://msdn.microsoft.com/en-us/library/4hwaceh6.aspx).
>
> Could someone please check whether math constants work in later versions
> of visual studio(Both with and without #define _USE_MATH_CONSTANTS)?
>
> Thank you
> Tanuj
>
>
-- 
Jeff McKenna
MapServer Consulting and Training Services
http://www.gatewaygeomatics.com/