[math.constants]

# 29 Numerics library [[numerics]](./#numerics)

## 29.8 Numbers [[numbers]](numbers#math.constants)

### 29.8.2 Mathematical constants [math.constants]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10887)

The library-defined partial specializations
of mathematical constant variable templates
are initialized with the nearest representable values ofe,log2e,log10e,π,1π,1√π,ln2,ln10,√2,√3,1√3,
the Euler-Mascheroni γ constant, and
the golden ratio φ constant 1+√52,
respectively[.](#1.sentence-1)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10906)

Pursuant to [[namespace.std]](namespace.std "16.4.5.2.1 Namespace std"),
a program may partially or explicitly specialize
a mathematical constant variable template
provided that the specialization depends on a program-defined type[.](#2.sentence-1)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10912)

A program that instantiates a primary template
of a mathematical constant variable template is ill-formed[.](#3.sentence-1)