Hands-On Design Patterns with C++

Variable template

The last kind of template in C++ is the variable template, which was introduced in C++14. This template allows us to define a variable with a generic type:

template <typename T>constexpr T pi = T(3.14159265358979323846264338327950288419716939937510582097494459230781L);pi<float>;     // 3.141592pi<double>;    // 3.141592653589793

Variable templates are not used in the rest of this book, so we will not mention them again.