我有摘录：
enum class EnumClass {
};
constexpr EnumClass m0 = static_cast<EnumClass>(0);
constexpr EnumClass m1 = static_cast<EnumClass>(1);
int main()
{
EnumClass aa = m0;
switch (aa) {
case m0 : break;
case m1 : break;
}
}
带有-Wall标志的Gcc 7.0合理警告我：
warning: case value '0' not in enumerated type 'EnumClass' [-Wswitch]
warning: case value '1' not in enumerated type 'EnumClass' [-Wswitch]
我想要的是摆脱这个警告。假设有很多这样的开关，所以每次手动关闭/打开此警告并不是很方便。此外，我不想全局关闭此诊断。
我想要的是以某种方式（可能在EnumClass定义中使用一些宏）向编译器说任何可能的int值都可以在EnumClass中。有人可以提出一些想法如何实现吗？
答案 0 :(得分：1)
我仍然不明白您的最终目标是什么，但是，假设您想要阻止仅在代码的某些特定部分生成using System;
using System.Threading;
using System.Collections.Generic;
using System.Linq;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
private void backgroundWorker1_DoWork(object sender, System.ComponentModel.DoWorkEventArgs e)
{
int sum = 0;
for (int i = 1; i <= 100; i++)
{
// run the process here
Thread.Sleep(100);
// end process
sum = sum + i;
backgroundWorker1.ReportProgress(i);
if (backgroundWorker1.CancellationPending)
{
e.Cancel = true;
backgroundWorker1.ReportProgress(0);
return;
}
}
// displays the sum of the process
e.Result = sum;
}
private void backgroundWorker1_ProgressChanged(object sender, System.ComponentModel.ProgressChangedEventArgs e)
{
progressBar1.Value = e.ProgressPercentage;
label5.Text = e.ProgressPercentage.ToString() + "%";
DateTime starttime = DateTime.Now;
var timespent = DateTime.Now - starttime;
double secondsremaining = (double)(timespent.TotalSeconds / progressBar1.Value) * (progressBar1.Maximum - progressBar1.Value);
label7.Text = "Time remaining:" + (int)secondsremaining;
Console.WriteLine(secondsremaining);
}
private void backgroundWorker1_RunWorkerCompleted(object sender, System.ComponentModel.RunWorkerCompletedEventArgs e)
{
if (e.Cancelled)
{
label5.Text = "Processing Cancelled";
}
else if (e.Error != null)
{
label5.Text = e.Error.Message;
}
else
{
label5.Text = "Sum = " + e.Result.ToString();
}
label6.Text = "";
}
private void button11_Click_1(object sender, EventArgs e)
{
//Checks if the background worker is busy running operations
if (!backgroundWorker1.IsBusy)
{
//this method will start the excution of the opreation
backgroundWorker1.RunWorkerAsync();
}
else
{
label6.Text = "The operation is being completed, please wait...";
}
}
}
}
}
警告，您可以使用{{1指令如下：
-Wswitch这不会全局停用#pragma - 它会在int main()
{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wswitch"
EnumClass aa = EnumClass::m0;
switch (aa) {
case EnumClass::m0 : break;
case EnumClass::m1 : break;
case static_cast<EnumClass>(888) : break;
}
#pragma GCC diagnostic pop
}
行恢复。