[Boost-bugs] [Boost C++ Libraries] #7379: Boost Format strings causing memory leaks

Subject: [Boost-bugs] [Boost C++ Libraries] #7379: Boost Format strings causing memory leaks
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2012-09-14 16:19:41

#7379: Boost Format strings causing memory leaks
----------------------------------------------------+-----------------------
 Reporter:  Jason Vincent <jason.vincent@…>         |       Owner:  samuel_krempp
     Type:  Bugs                                    |      Status:  new          
Milestone:  To Be Determined                        |   Component:  format       
  Version:  Boost 1.44.0                            |    Severity:  Problem      
 Keywords:  format memory leak                      |  
----------------------------------------------------+-----------------------
 I determined that certain format string used in a boost::wformat object
 will leak memory.  I was using a formatter to convert a value to a
 floating point value with and without a percent symbol at the end.

 The two format strings I was using were:


 {{{
 L"%1$.1f"
 }}}
  - format with one decimal place of precision[[BR]]

 {{{
 L"%1$.0f %%"
 }}}
  - format with no decimal places but add a percent sign

 I determined that removing the "%%" reduced some of the memory leaks, and
 removing the "$.1f" or "$.0f" eliminated the remaining memory leaks.

 This was done using Boost v 1.44 with Visual Studio 2010 on Win 7 64-bit.


 For more context here is part of the code that I can share:

 note, mFormatter is a boost::wformat member object


 {{{
 MyObject::MyObject() :
     mNumDecimalPlaces   (1),
     mFormatter          (L"%1$.1f")  //--- THIS LEAKED
 {
 }


 std::wstring MyObject::PercentToString(const FLOAT iMin,
                                        const FLOAT iMax,
                                        const FLOAT iPercent)
 {
     FLOAT value = PercentToValue(iMin, iMax, iPercent);

     return boost::str(mFormatter % value); //--- THIS LEAKED
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7379>
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