This header is part of thenumeric library.
The header<numbers> provides several mathematical constants, such asstd::numbers::pi orstd::numbers::sqrt2
namespace std::numbers{template<class T>inlineconstexpr T e_v=/* unspecified */;template<class T>inlineconstexpr T log2e_v=/* unspecified */;template<class T>inlineconstexpr T log10e_v=/* unspecified */;template<class T>inlineconstexpr T pi_v=/* unspecified */;template<class T>inlineconstexpr T inv_pi_v=/* unspecified */;template<class T>inlineconstexpr T inv_sqrtpi_v=/* unspecified */;template<class T>inlineconstexpr T ln2_v=/* unspecified */;template<class T>inlineconstexpr T ln10_v=/* unspecified */;template<class T>inlineconstexpr T sqrt2_v=/* unspecified */;template<class T>inlineconstexpr T sqrt3_v=/* unspecified */;template<class T>inlineconstexpr T inv_sqrt3_v=/* unspecified */;template<class T>inlineconstexpr T egamma_v=/* unspecified */;template<class T>inlineconstexpr T phi_v=/* unspecified */; template<floating_point T>inlineconstexpr T e_v<T>=/* see description */;template<floating_point T>inlineconstexpr T log2e_v<T>=/* see description */;template<floating_point T>inlineconstexpr T log10e_v<T>=/* see description */;template<floating_point T>inlineconstexpr T pi_v<T>=/* see description */;template<floating_point T>inlineconstexpr T inv_pi_v<T>=/* see description */;template<floating_point T>inlineconstexpr T inv_sqrtpi_v<T>=/* see description */;template<floating_point T>inlineconstexpr T ln2_v<T>=/* see description */;template<floating_point T>inlineconstexpr T ln10_v<T>=/* see description */;template<floating_point T>inlineconstexpr T sqrt2_v<T>=/* see description */;template<floating_point T>inlineconstexpr T sqrt3_v<T>=/* see description */;template<floating_point T>inlineconstexpr T inv_sqrt3_v<T>=/* see description */;template<floating_point T>inlineconstexpr T egamma_v<T>=/* see description */;template<floating_point T>inlineconstexpr T phi_v<T>=/* see description */; inlineconstexprdouble e= e_v<double>;inlineconstexprdouble log2e= log2e_v<double>;inlineconstexprdouble log10e= log10e_v<double>;inlineconstexprdouble pi= pi_v<double>;inlineconstexprdouble inv_pi= inv_pi_v<double>;inlineconstexprdouble inv_sqrtpi= inv_sqrtpi_v<double>;inlineconstexprdouble ln2= ln2_v<double>;inlineconstexprdouble ln10= ln10_v<double>;inlineconstexprdouble sqrt2= sqrt2_v<double>;inlineconstexprdouble sqrt3= sqrt3_v<double>;inlineconstexprdouble inv_sqrt3= inv_sqrt3_v<double>;inlineconstexprdouble egamma= egamma_v<double>;inlineconstexprdouble phi= phi_v<double>;}