golang 将 big.Float 转换为 big.Int

将big.Float转换为big.Int，我在下面编写代码，但它溢出了uint64，那么将big.Float转换为big.Int的正确方法是什么。

package main

import "fmt"
import "math/big"

func FloatToBigInt(val float64) *big.Int {
    bigval := new(big.Float)
    bigval.SetFloat64(val)

    coin := new(big.Float)
    coin.SetInt(big.NewInt(1000000000000000000))
    bigval.Mul(bigval, coin)

    result := new(big.Int)
    f,_ := bigval.Uint64()
    result.SetUint64(f)

    return result
}

func main() {
    fmt.Println("vim-go")
    fmt.Println(FloatToBigInt(float64(10)))
    fmt.Println(FloatToBigInt(float64(20)))
    fmt.Println(FloatToBigInt(float64(30)))
    fmt.Println(FloatToBigInt(float64(40)))
    fmt.Println(FloatToBigInt(float64(50)))
    fmt.Println(FloatToBigInt(float64(100)))
    fmt.Println(FloatToBigInt(float64(1000)))
    fmt.Println(FloatToBigInt(float64(10000)))
}

一个大整数大于uint64总是会导致溢出uint64有固定大小。您应该使用以下内容method https://golang.org/pkg/math/big/#Float.Int on *Float:

func (*Float) Int

所需的更改是：

func FloatToBigInt(val float64) *big.Int {
    bigval := new(big.Float)
    bigval.SetFloat64(val)
    // Set precision if required.
    // bigval.SetPrec(64)

    coin := new(big.Float)
    coin.SetInt(big.NewInt(1000000000000000000))

    bigval.Mul(bigval, coin)

    result := new(big.Int)
    bigval.Int(result) // store converted number in result

    return result
}

工作示例：https://play.golang.org/p/sEhH6iPkrK https://play.golang.org/p/sEhH6iPkrK