Why Can't I Get the Address of a Constant in Go?

Why Can't You Directly Retrieve the Address of a Constant in Go?

While attempting to determine the address of a constant, you might encounter an error like "cannot take the address of a constant." This occurs because Go imposes limitations on the address operator, prohibiting the use of constants as its operands.

The Go specification dictates that addressable entities include variables, pointer indirections, slice indexing operations, field selectors of addressable structs, array indexing operations of addressable arrays, and composite literals. However, constants are conspicuously absent from this list.

This restriction stems from two fundamental reasons:

1. Absence of Addresses: Constants may not have intrinsic addresses, especially when optimized by the compiler.
2. Preservation of Immutability: Allowing address acquisition for constants would compromise their immutable nature. Alterations to values pointed to by such addresses could wreak havoc on the integrity of your codebase.

To circumvent this limitation, you can assign the constant value to an addressable variable and acquire the address of the variable instead. For instance:

package main

func main() {
    const k = 5
    v := k
    address := &v // This approach is allowed
}

However, consider that numeric constants in Go possess arbitrary precision, meaning they can exceed the maximum value representable by a particular type. Assigning a constant to a variable may result in precision loss, especially in the case of floating-point constants.

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