Go中的C ++ fmod等效于什么？

fmod Compute remainder of division Returns the floating-point remainder of numer/denom (rounded towards zero):

fmod = numer - tquot * denom

Where tquot is the truncated (i.e., rounded towards zero) result of: numer/denom.

http://www.cplusplus.com/reference/cmath/fmod/

Package math

import "math" 

func Mod

func Mod(x, y float64) float64

Mod returns the floating-point remainder of x/y. The magnitude of the result is less than y and its sign agrees with that of x.

For example,

package main

/*
#cgo LDFLAGS: -lm

#include <math.h>
#include <stdio.h>

double fmodC(double x, double y) {
    double mod = fmod(x, y);
    printf("%f
", mod);
    return mod;
}
*/
import "C"

import (
    "fmt"
    "math"
)

func fmodGo(x, y float64) float64 {
    mod := math.Mod(x, y)
    fmt.Printf("%f
", mod)
    return mod
}

func main() {
    x, y := 42.0*3.14159, -2.718
    fmt.Println(x, y)
    modC := C.fmodC(C.double(x), C.double(y))
    modGo := fmodGo(x, y)
    fmt.Println(float64(modC) == modGo)

    // fmod = numer - tquot * denom
    numer := x
    denom := y
    tquot := float64(int64(x / y))
    fmod := math.Mod(numer, denom)
    fmt.Println(fmod == numer-tquot*denom)
}

Output:

131.94678 -2.718
1.482780
1.482780
true
true