macOS Weird question when output results to file.

[pliuya]

I just started using Xcode and met with a very weird question while outputting results to file. Codes are follows:
#include <iostream>
#include <math.h>
#include <fstream>

using namespace std;

int main()
{

ofstream trial;
trial.open("trial.txt");
trial << "****" << endl;
trial << (5+3) << endl;
return 0;

}
The outputs in trial.txt are
****
I suppose to see 8 but it doesn't appear. However, the results are correct when output to console:
****
8

Does anyone have idea why it happened? Your help will be highly appreciated.

Best,
Stanley

 

[kpua]

You're not closing the stream, so the buffer isn't being flushed and the file contents not written.

 

[pliuya]

Thank you, but not the case.

Even I add trial.close(), the problem is still there. I am pretty sure it is due to Xcode. Maybe I miss something in the configuration. There is no problem when I run it using Eclipse.

 

[Detrius]

We get this question every couple days. It's actually an Xcode bug. Edit your target settings and look for this:

Preprocessor Macros = _GLIBCXX_DEBUG=1 _GLIBCXX_DEBUG_PEDANTIC=1


Highlight the line, and press the delete key on your keyboard. Now try again.

 

[pliuya]

Thanks. It works.

Thank you, Detrius! I follow what you say:
1. Project -> Edit Active Target ...
2. Search for "preprocessor" in Build
3. Delete the value.

It works correctly!!