src/internal/poll/errno_windows.go

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

//go:build windows
// +build windows

package poll

import "syscall"

// Do the interface allocations only once for common
// Errno values.

var (
	errERROR_IO_PENDING error = syscall.Errno(syscall.ERROR_IO_PENDING)
)

// ErrnoErr returns common boxed Errno values, to prevent
// allocations at runtime.
func errnoErr(e syscall.Errno) error {
	switch e {
	case 0:
		return nil
	case syscall.ERROR_IO_PENDING:
		return errERROR_IO_PENDING
	}
	// TODO: add more here, after collecting data on the common
	// error values see on Windows. (perhaps when running
	// all.bat?)
	return e
}