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Mathematical constants

From cppreference.com
< cpp‎ | numeric

[edit] Constants (since C++20)

Defined in header <numbers>
Defined in namespace std::numbers
e_v
the mathematical constant e
(variable template)
log2e_v
log
2
e

(variable template)
log10e_v
log
10
e

(variable template)
pi_v
π
(variable template)
inv_pi_v
1
π

(variable template)
inv_sqrtpi_v
1
π

(variable template)
ln2_v
ln 2
(variable template)
ln10_v
ln 10
(variable template)
sqrt2_v
2
(variable template)
sqrt3_v
2
(variable template)
inv_sqrt3_v
1
3

(variable template)
egamma_v
the Euler–Mascheroni constant
(variable template)
phi_v
the golden ratio Φ constant (
1 + 5
2
)
(variable template)
inline constexpr double e
e_v<double>
(constant)
inline constexpr double log2e
log2e_v<double>
(constant)
inline constexpr double log10e
log10e_v<double>
(constant)
inline constexpr double pi
pi_v<double>
(constant)
inline constexpr double inv_pi
inv_pi_v<double>
(constant)
inline constexpr double inv_sqrtpi
inv_sqrtpi_v<double>
(constant)
inline constexpr double ln2
ln2_v<double>
(constant)
inline constexpr double ln10
ln10_v<double>
(constant)
inline constexpr double sqrt2
sqrt2_v<double>
(constant)
inline constexpr double sqrt3
sqrt3_v<double>
(constant)
inline constexpr double inv_sqrt3
inv_sqrt3_v<double>
(constant)
inline constexpr double egamma
egamma_v<double>
(constant)
inline constexpr double phi
phi_v<double>
(constant)

[edit] Notes

A program that instantiates a primary template of a mathematical constant variable template is ill-formed.

The standard library specializes mathematical constant variable templates for all floating-point types (i.e. float, double and long double).

A program may partially or explicitly specialize a mathematical constant variable template provided that the specialization depends on a program-defined type.