cppunit测试一个大数运算，大数运算用的参数是list

[man-douer]

求指点
错误如下：
--------------------Configuration: UnitTest - Win32 Debug--------------------
Compiling...
PlusTestCase.cpp
d:\cppunit-1.12.1\include\cppunit\testassert.h(49) : error C2679: binary '<<' : no operator defined which takes a right-hand operand of type 'const class std::list<char,class std::allocator<char> >' (or there is no acceptable conversion)
d:\cppunit-1.12.1\include\cppunit\testassert.h(47) : while compiling class-template member function 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl CppUnit::assertion_traits<class std::list<ch
ar,class std::allocator<char> > >::toString(const class std::list<char,class std::allocator<char> > &)'
执行 cl.exe 时出错.