dictionary - 为什么 Golang 不允许 const 映射？

Question

我想创建一个如下所示的常量映射:

const (
    running = map[string]string{
        "one": "ONE",
        "two": "TWO",
    }
)

但是每当我这样做时，我都会收到以下错误:

const initializer map[string]字符串字面量不是常量

为什么会这样，为什么 Golang 不像其他变量一样对待它们？

Answer 1

来自 https://golang.org/ref/spec#Constants :

A constant value is represented by a rune, integer, floating-point, imaginary, or string literal, an identifier denoting a constant, a constant expression, a conversion with a result that is a constant, or the result value of some built-in functions such as unsafe.Sizeof applied to any value, cap or len applied to some expressions, real and imag applied to a complex constant and complex applied to numeric constants.

tl;dr 只有数字类型，字符串和 bool 值可以是常量，数组、 slice 和映射不是数字类型。