0.9.9/api/a00236_source.html

 #pragma once

 // Dependencies
 #include "../detail/setup.hpp"

 #if GLM_MESSAGES == GLM_ENABLE && !defined(GLM_EXT_INCLUDED)
 #   pragma message("GLM: GLM_EXT_scalar_constants extension included")
 #endif

 namespace glm
 {

     template<typename genType>
     GLM_FUNC_DECL GLM_CONSTEXPR genType epsilon();

     template<typename genType>
     GLM_FUNC_DECL GLM_CONSTEXPR genType pi();

 } //namespace glm

 #include "scalar_constants.inl"
glm::pi
GLM_FUNC_DECL GLM_CONSTEXPR genType pi()
Return the pi constant for floating point types.

glm::epsilon
GLM_FUNC_DECL GLM_CONSTEXPR genType epsilon()
Return the epsilon constant for floating point types.

glm
Definition: common.hpp:20