C++ custom stream manipulator that changes next item on stream -


You print this number in hexadecimal in C ++: 

  Int num = 10; Std :: cout & lt; & Lt; Std :: hex & lt; & Lt; Number; // = & gt; 'A'

I know that I can make a manipulator which adds stuff to the stream like this: 

  std :: ostream & Amp; Windows_feed (std :: ostream and out) {out & lt; & Lt; "\ R \ n"; Return; } Std :: cout & lt; & Lt; "Hello" & lt; & Lt; Windows_feed; // = & gt; "Hello \ r \ n"

How, though, can I create a manipulator, such as 'hex', modifying objects to come in currents? As a simple example, how do I make a Ploson Manipater here?: 

  int num2 = 1; Std :: cout & lt; & Lt; "1 + 1 =" & lt; & Lt; Plason & lt; & Lt; NUM2; // = & gt; "1 + 1 = 2" // Note that the values ​​stored in num2 do not change, only the display above it. Std :: cout & lt; & Lt; NUM2; // = & gt; First, you have to store some states in each stream. You can do this with that task and index, by which:  
  inline int geti () {static int i = ios_base :: xalloc (); Return i; } Ostream & amp; amp; Add_one (Ostream and OS) {os.iword (geti ()) = 1; Return os; } Ostream & amp; amp; Add_none (Ostream and OS) {os.iword (geti ()) = 0; Return os; }  
 
 Being in place, you can already get some states in all the streams. Now, you just have to hook in the related output operation. Numerical output is done by one aspect, because this is probably dependent on the locale. Then you 
 
  struct my_num_put: num_put & lt; Char & gt; can do. {Iter_type do_put (iter_type s, ios_base & amp; F; char_type fill, long v) const {return num_put & lt; Char & gt; :: do_put (s, f, fill, v + f.iword (geti ())); } Iter_type do_put (iter_type s, ios_base & amp; f, char_type fill, unsigned long v) const {return num_put & lt; Char & gt; :: do_put (s, f, fill, v + f.iword (geti ())); }};  
 
 Now, you can test the stuff. 
 
  int main (// output: 11121011 cout.imbue (locale, new my_num_put)); Cout & lt; & Lt; Add_one & lt; & Lt; 10 & lt; & Lt; 11 & lt; & Lt; Add_none & lt; & Lt; 10 & lt; & Lt; 1 1; }  
 
 If you want only the next number to increase, simply set  0  to each code on  do_put .

Comments

Post a Comment

Popular posts from this blog

python - Overriding the save method in Django ModelForm -

I'm having trouble overriding a ModelForm save method. I get this error I'm: Exception type: TypeErier Exception Value: Save () found an unexpected keyword argument 'committed' My intentions include a form 3 fields Submit several values ​​for, then create an object for each combination of those areas, and to save each object file models.py class collarsult type (models.Model): id = model. AutoField (db_column = 'icontact_result_code_type_id', primary_key = true) callResult = models.ForeignKey ( 'CallResult', db_column = 'icontact_result_code_id') campaign = models.ForeignKey ( 'campaign', db_column = 'icampaign_id') CALLTYPE = models.ForeignKey ( 'CALLTYPE', db_column = 'icall_type_id') agent = models.BooleanField (db_column = 'bagent', default = true) teamLeader = models.BooleanField (db_column = 'bTeamLeader', default = true) active = models.BooleanField (db_column = Django.form...
Read more

html - CSS autoheight, but fit content to height of div -

I have a div in which there are three children- div in the left and middle div: float: left while true: float: true because it is my layout Actually will spoil, I've used ClearFix Hack: .cf {zoom: 1; }. Cf: First,. Cf: {content: ""; Display: Table; }. Cf: After {clear: both; } It still works, but I want to be the right div an indicator. So it should fill 100% of the parent unit of height. How can I complete this? PS is the full code: & Lt; / Div & gt; & Lt; Div class = "mobile_content" & gt; & Lt; H5 & gt; {{Data.titel}} & lt; / H5> & Lt; Table & gt; & Lt; TR & gt; & Lt; Th & gt; Komponist: & lt; / Th & gt; & Lt; TD & gt; {{Data.komponist}} & lt; / TD & gt; & Lt; / TR & gt; & Lt; TR & gt; & Lt; Th & gt; Instrument: & lt; / Th & gt; & Lt; TD & gt; {{Data.instrumente}} & lt; / TD & gt; & Lt; / TR & gt;...
Read more

qt - How to prevent QAudioInput from automatically boosting the master volume to 100%? -

I have been trying to use Qt5 multimedia to record audio with QAudioInput, however, when I see If QAudioInput is started, it increases the master volume of my sound device to 100%. How can I prevent QAudioInput from changing the master volume? My current development platform is Linux with PalsAdio (with flat audio disabled). How can I use QAudioInput : QAudioDeviceInfo device_info = QAudioDeviceInfo :: defaultInputDevice (); QAudio format format; Format.setSampleRate (44100); Format.setChannelCount (1); Format.setSampleSize (16); Format.setCodec ("Audio / PCM"); Format.setSampleType (QAudioFormat :: SignedInt); Format.setByteOrder (QAudioFormat :: LittleEndian); Std :: cout & lt; & Lt; Device_info.deviceName (). ToUtf8 (). ConstData () & lt; & Lt; Std :: endl; QAudioInput * default_device = new QAudioInput (device_info, format); QIODevice * default_io_device = default_device-> Start (); a QAudioInput.setVolume () method is not you I ...
Read more