[Bug c++/54775] New: string error

["zerolxy at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54775

             Bug #: 54775
           Summary: string error
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zerolxy@gmail.com


I am using Eclipse, GCC 4.8 and building C++ project on both Mac OS 10.7 and
10.8. For the most of the time, the project builds and runs properly except for
some specific functions. For example:

int main( int argc, char ** argv ) {
    string a = "test";
    string b = "-bla";
    string c;
    c = a + b;
    return 0;
}
The compile is successful:

Build of configuration Debug for project Working **

make all Building file: ../working.cpp Invoking: GCC C++ Compiler g++ -O0 -g3
-Wall -c -fmessage-length=0 -std=c++11 -MMD -MP -MF"working.d" -MT"working.d"
-o "working.o" "../working.cpp" Finished building: ../working.cpp Building
target: Working Invoking: MacOS X C++ Linker g++ -o "Working" ./working.o
Finished building target: Working

Build Finished **

However, I received this runtime error:

dyld: lazy symbol binding failed: Symbol not found: __ZNSsaSEOSs
  Referenced from: /Volumes/Macintosh
HD/Users/zeroliu/Study/CPP/Working/Debug/Working
  Expected in: /usr/lib/libstdc++.6.dylib

dyld: Symbol not found: __ZNSsaSEOSs
  Referenced from: /Volumes/Macintosh
HD/Users/zeroliu/Study/CPP/Working/Debug/Working
  Expected in: /usr/lib/libstdc++.6.dylib
I find that the error comes from

string c;
c = a + b; 
The interesting thing is, if I make the following changes:

string c = a+b;
or

c = a;
The programs runs perfectly.