Proposal: expression to create pointer to simple types

Re:Proposal: expression to create pointer to simple types by friseurtermin on Monday April 19, 2021 @01:00PM (#26865071)

Ok I think I'm not understanding this correctly then. Why does this return an error?

    package main

    import (
        "fmt"
    )
    
    const tst = 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
    
    func main() {
        fmt.Println("%v", tst)
    }

Error: ./prog.go:16:17: constant 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 overflows int

See: https://play.golang.org/p/47l5qAsXD5r

[ Parent | on HN ]

Re:Proposal: expression to create pointer to simple types by howeyc on Monday April 19, 2021 @01:22PM (#26865411)

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

> An untyped constant has a default type which is the type to which the constant is implicitly converted in contexts where a typed value is required.

The default type for a number (integer) is int. If you were to add a period in that long string of zeros, the default for floating-point is float64.

[ Parent | on HN ]

Re:Proposal: expression to create pointer to simple types by HALtheWise on Monday April 19, 2021 @04:57PM (#26867904)

If you look closely, that error happens at the print line statement, not at the constant declaration. The constant is perfectly legal to exist as written, and you can even do constant operations like mathematics on it, you just can't legally assign it to a variable (implicitly in this case as part of the function call) if it's value is too large for the type of that variable.

[ Parent | on HN ]

Re:Proposal: expression to create pointer to simple types by friseurtermin on Tuesday April 20, 2021 @04:24AM (#26872094)

I see, that makes sense. Thanks!

[ Parent | on HN ]