Fails to build (error: taking address of rvalue [-fpermissive])

[jose1711]

*** omake: reading OMakefiles
*** omake: finished reading OMakefiles (0.10 sec)
- build . dlg_settings_ex.o                                                                                                                                                                                        
+ /usr/bin/c++ -fPIC -std=c++11 -Wall -O2 -funroll-loops -DLOCALEDIR='"/usr/share/locale"' -DRESOURCEDIR='"/usr/share/res"' -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -g -ffile-prefix-map=/build/fltk/src=/usr/src/debug/fltk -flto=auto -ffat-lto-objects -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_THREAD_SAFE -D_REENTRANT -I. -c -o dlg_settings_ex.o dlg_settings_ex.cpp
dlg_settings_ex.cpp: In member function ‘void dlg_settings::tab_ui_setup_ex()’:
dlg_settings_ex.cpp:197:88: error: taking address of rvalue [-fpermissive]
  197 |     m_input_trackwidth->value(static_cast<std::ostringstream*>( &(std::ostringstream() << m_cfgui.tracklinewidth()) )->str().c_str());
      |                                                                  ~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
*** omake: 146/181 targets are up to date                                                                                                                                                                          
*** omake: failed (14.30 sec, 23/23 scans, 36/36 rules, 110/241 digests)
*** omake: targets were not rebuilt because of errors:                                                                                                                                                             
   dlg_settings_ex.o
      depends on: dlg_settings_ex.cpp

[4fury-c3440d8]

#6 clang compiler fix