package main

	// typedef int (*intFunc) ();
	//
	// int
	// bridge_int_func(intFunc f)
	// {
	//		return f();
	// }
	//
	// int fortytwo()
	// {
	//	    return 42;
	// }
	import "C"
	import "fmt"

	func main() {
		f := C.intFunc(C.fortytwo)
		fmt.Println(int(C.bridge_int_func(f)))
		// Output: 42
	}

In C, a function argument written as a fixed size array

pkg syscall (netbsd-arm64-cgo), const IFT_BGPPOLICYACCOUNTING = 162
pkg syscall (netbsd-arm64-cgo), const IFT_BGPPOLICYACCOUNTING ideal-int
pkg syscall (netbsd-arm64-cgo), const IFT_BRIDGE = 209
pkg syscall (netbsd-arm64-cgo), const IFT_BRIDGE ideal-int
pkg syscall (netbsd-arm64-cgo), const IFT_BSC = 83
pkg syscall (netbsd-arm64-cgo), const IFT_BSC ideal-int
pkg syscall (netbsd-arm64-cgo), const IFT_CARP = 248

pkg syscall (darwin-386), const IFT_ARCNET = 35
pkg syscall (darwin-386), const IFT_ARCNETPLUS = 36
pkg syscall (darwin-386), const IFT_ATM = 37
pkg syscall (darwin-386), const IFT_BRIDGE = 209
pkg syscall (darwin-386), const IFT_CARP = 248
pkg syscall (darwin-386), const IFT_CELLULAR = 255
pkg syscall (darwin-386), const IFT_CEPT = 19
pkg syscall (darwin-386), const IFT_DS3 = 30

pkg syscall (freebsd-386-cgo), const IFT_ATMVIRTUAL ideal-int
pkg syscall (freebsd-386-cgo), const IFT_BGPPOLICYACCOUNTING ideal-int
pkg syscall (freebsd-386-cgo), const IFT_BRIDGE ideal-int
pkg syscall (freebsd-386-cgo), const IFT_BSC ideal-int
pkg syscall (freebsd-386-cgo), const IFT_CARP ideal-int
pkg syscall (freebsd-386-cgo), const IFT_CCTEMUL ideal-int

// with full definitions instead of mangled names.
func (p *Package) rewriteRef(f *File) {
	// Keep a list of all the functions, to remove the ones
	// only used as expressions and avoid generating bridge
	// code for them.
	functions := make(map[string]bool)

	for _, n := range f.Name {
		if n.Kind == "func" {
			functions[n.Go] = false
		}
	}

pkg syscall (darwin-arm64), const IFT_ARCNETPLUS ideal-int
pkg syscall (darwin-arm64), const IFT_ATM = 37
pkg syscall (darwin-arm64), const IFT_ATM ideal-int
pkg syscall (darwin-arm64), const IFT_BRIDGE = 209
pkg syscall (darwin-arm64), const IFT_BRIDGE ideal-int
pkg syscall (darwin-arm64), const IFT_CARP = 248
pkg syscall (darwin-arm64), const IFT_CARP ideal-int
pkg syscall (darwin-arm64), const IFT_CELLULAR = 255

pkg syscall (freebsd-arm64), const IFT_BGPPOLICYACCOUNTING = 162
pkg syscall (freebsd-arm64), const IFT_BGPPOLICYACCOUNTING ideal-int
pkg syscall (freebsd-arm64), const IFT_BRIDGE = 209
pkg syscall (freebsd-arm64), const IFT_BRIDGE ideal-int
pkg syscall (freebsd-arm64), const IFT_BSC = 83
pkg syscall (freebsd-arm64), const IFT_BSC ideal-int
pkg syscall (freebsd-arm64), const IFT_CARP = 248

pkg syscall (darwin-386), const IFT_ARCNET ideal-int
pkg syscall (darwin-386), const IFT_ARCNETPLUS ideal-int
pkg syscall (darwin-386), const IFT_ATM ideal-int
pkg syscall (darwin-386), const IFT_BRIDGE ideal-int
pkg syscall (darwin-386), const IFT_CARP ideal-int
pkg syscall (darwin-386), const IFT_CELLULAR ideal-int
pkg syscall (darwin-386), const IFT_CEPT ideal-int
pkg syscall (darwin-386), const IFT_DS3 ideal-int

pkg syscall (freebsd-riscv64), const IFT_BGPPOLICYACCOUNTING = 162 #53466
pkg syscall (freebsd-riscv64), const IFT_BGPPOLICYACCOUNTING ideal-int #53466
pkg syscall (freebsd-riscv64), const IFT_BRIDGE = 209 #53466
pkg syscall (freebsd-riscv64), const IFT_BRIDGE ideal-int #53466
pkg syscall (freebsd-riscv64), const IFT_BSC = 83 #53466
pkg syscall (freebsd-riscv64), const IFT_BSC ideal-int #53466
pkg syscall (freebsd-riscv64), const IFT_CARP = 248 #53466

	init bool
}

// NewInt returns a new Int initialized to x.
func NewInt(x int64) *Int { return new(Int).SetInt64(x) }

// Int promises that the zero value is a 0, but in gmp
// the zero value is a crash.  To bridge the gap, the
// init bool says whether this is a valid gmp value.
// doinit initializes z.i if it needs it.  This is not inherent
// to FFI, just a mismatch between Go's convention of