TCLAP issus with parsing std::wstring

Question

TCLAP std::wstring issue. Hello All,

I am using TCLAP(command line parsing utility). It has worked well so far until I ran into issues with wstring processing capability.

I have the below line to parse code for an UnlabeledValueArg

std::wstring defaultValue; 

UnlabeledValueArg<std::wstring>
serverName("COMPUTERNAME", "List all scheduled tasks of computer", false,
           defaultValue, "string" );

I run into compile time issues ( Visual Studio spits out incredulous amounts of issues.). My question is have anyone tried using std::wstring with TCLAP. If yes can you post the solution or the approach to it. Thanks.

Edit - The compiler warnings I get is -

C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/StandardTraits.h(187) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'const std::string' (or there is no acceptable conversion)
    c:\Program Files (x86)\Microsoft Visual Studio
9.0\VC\include\xstring(914): could be 'std::basic_string<_Elem,_Traits,_Ax>

&std::basic_string<_Elem,_Traits,_Ax>::operator

=(const std::basic_string<_Elem,_Traits,_Ax> &)' with [ _Elem=wchar_t, _Traits=std::char_traits, _Ax=std::allocator ]
    c:\Program Files (x86)\Microsoft Visual Studio
9.0\VC\include\xstring(919): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(const _Elem *)' with [ _Elem=wchar_t, _Traits=std::char_traits, _Ax=std::allocator ]
    c:\Program Files (x86)\Microsoft Visual Studio
9.0\VC\include\xstring(924): or 'std::basic_string<_Elem,_Traits,_Ax> &std::basic_string<_Elem,_Traits,_Ax>::operator =(_Elem)' with [ _Elem=wchar_t, _Traits=std::char_traits, _Ax=std::allocator ] while trying to match the argument list '(std::wstring, const std::string)'
    C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/Arg.h(446)
: see reference to function template instantiation 'void TCLAP::SetString(T &,const std::string &)' being compiled with [ T=std::wstring ]
    C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/ValueArg.h(391)
: see reference to function template instantiation 'void TCLAP::ExtractValue(T &,const std::string &,TCLAP::StringLike)' being compiled with [ T=std::wstring ]
    C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/ValueArg.h(389)
: while compiling class template member function 'void TCLAP::ValueArg::_extractValue(const std::string &)' with [ T=std::wstring ]
    C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/ValueArg.h(325)
: while compiling class template member function 'bool TCLAP::ValueArg::processArg(int *,std::vector<_Ty> &)' with [ T=std::wstring, _Ty=std::string ]
    C:\DevProjects\MyProjects\nttoolkit\trunk\external\tclap/UnlabeledValueArg.h(44)
: see reference to class template

instantiation 'TCLAP::ValueArg' being compiled with [ T=std::wstring ]
    C:\DevProjects\MyProjects\nttoolkit\trunk\tasksecure\src\main.cpp(26)
: see reference to class template instantiation 'TCLAP::UnlabeledValueArg' being compiled with [ T=std::wstring ]

TaskSecure - 1 error(s), 6 warning(s)

Blazes Blazes · Accepted Answer · 2011-05-18T15:00:58

I downloaded the source and built your example. The UnlabeledValueArg does take std::string, so apologies. The StandardTraits.h:202 shows dst = src. It is trying to set std::string to a std::wstring and there is no conversion. Apparently, TCLAP does not support std::wstring. The src should be std::wstring.

One work around might be to use std::string instead, and UTF-8 encode your program's arguments before using TCLAP.

Another option is to ask the owner of TCLAP to extend it to support either wide and narrow arguments.

TCLAP issus with parsing std::wstring

1 Answers