如何在C ++中通过表达式定义常量？

Question

I need some like this:

const float ratio = 1/60;

How to do this?

Answer 1

正如您所做的那样，但告诉编译器表达式中的值是带有“f”后缀的浮点数

const float ratio = 1.0f/60.0f;

Answer 2

你真的不需要constexpr ，这将在C或C++ ：

const float ratio = 1./60;

Answer 3

If you need a ratio, as opposed to the result of one, you can use std::ratio :

constexpr one_sixtieth = std::ratio<1, 60>();

constexpr auto n = one_sixtieth.num;
constexpr auto d = one_sixtieth.den;

It comes with a set of useful compile time operations .

Answer 4

You try this

const float numerator =1;
const float denominator =60;
const float ratio = numerator/denominator;