Mar 28, 2012 · Calculating PI value is one of the complex problem and wikipedia talks about the approximations done for it and says it's difficult to calculate PI accurately. How does C …

Jun 29, 2012 · Just define the constant yourself (you can use the name M_PI freely, but should you want to be able to compile the code with a non-conforming compiler, you must first check …

Nov 13, 2009 · 653 I want to use the PI constant and trigonometric functions in some C++ program. I get the trigonometric functions with include <math.h>. However, there doesn't seem …

32 M_PI is defined by "a standard", if not a language standard: POSIX with the X/Open System Interfaces extension (which is very commonly supported and required for official UNIX …

Apr 11, 2018 · Does STL contain definition for pi (=3.14...)? Certainly, I can use old good M_PI, but it is non-standard and not cross-compiler compliant.

C++ headers have macros, includes, variables, functions and classes -- declared, defined or both. Now depending on a few flags (lookup conditional compilation) the pre-processor includes / …

Mar 5, 2013 · pi isn't a standard constant in Cocoa headers I have included, nor is PI. M_PI is the standard definition from math.h, and should be fine for most purposes.

Mar 13, 2014 · First, it's better to use a common standard definition of PI, like in the C standard header, <math.h>, where it is defined as #define M_PI 3.14159265358979323846. If you …

Aug 21, 2013 · Or I need to define it myself in one of my own headers. Or I have to use boost and all that. It just annoys me, that there isn't a standard c++ header defining that constant in a …

It's simple: M_PI is not defined in standard C. Provide your own definition if you want to be standard-compliant. C compilers cannot introduce such constants without breaking legal C …