c++ - 代码用 g++ 编译但用 VC++ 10 失败

Question

我正在将我的一些 Linux 程序移植到 Windows。我想确保我的代码在没有太多 #define 和 #ifdef 魔术的情况下同时使用 MinGW 和 Visual C++ 10 进行编译。除了这个问题，我已经设法解决了大部分问题。我有一个类似于以下的代码，它可以很好地使用 g++ 4.6.3 进行编译，但不能使用 Visual C++ 10:

#include <iostream>
#include <vector>
#include <array>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iterator>

typedef unsigned char UINT8;
const UINT8 MAX_COLL = 10;

template< typename BaseT, typename ExpT >
struct fopow {
    BaseT operator() ( BaseT base, ExpT exp ) const {
        return std::pow( base, exp );
    }
};

int main() {
    using namespace std;
    using namespace std::placeholders;

    array<int, MAX_COLL> intCollection_init = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    vector<int> intCollection( intCollection_init.begin(), intCollection_init.end() );

    transform( intCollection.begin(), intCollection.end(),
               ostream_iterator<int>( cout, " " ),
               bind( fopow<int, int>(), 3, _1 )
            );
    cout << endl;

    transform( intCollection.begin(), intCollection.end(),
               ostream_iterator<int>( cout, " " ),
               bind( fopow<int, int>(), _1, 3 )
            );
    cout << endl;
}

编译器的输出对我来说甚至是遥不可及的:

Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.40219.01 for 80x86
Copyright (C) Microsoft Corporation.  All rights reserved.

Test2.cpp C:\Program Files\Microsoft Visual Studio
10.0\VC\INCLUDE\xxresult(28) : error C2903: 'result' : symbol is neither a class template nor a function template
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : see reference to class tem plate instantiation 'std::tr1::_Result_type2<__formal,_Fty,_Arg0,_Arg1>' being compiled
        with
        [
            __formal=false,
            _Fty=fopow<int,int>,
            _Arg0=std::tr1::_Nil &,
            _Arg1=std::tr1::_Nil &
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(597) : see reference to class te mplate instantiation 'std::tr1::_Result_of2<_Fty,_Farg0,_Farg1>' being compiled
        with
        [
            _Fty=fopow<int,int>,
            _Farg0=std::tr1::_Nil &,
            _Farg1=std::tr1::_Nil &
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xrefwrap(28) : see reference to class tem plate instantiation 'std::tr1::_Result_of<_Ty>' being compiled
        with
        [
            _Ty=fopow<int,int> (std::tr1::_Nil &,std::tr1::_Nil &)
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxbind1(273) : see reference to class tem plate instantiation 'std::tr1::result_of<_Fty>' being compiled
        with
        [
            _Fty=fopow<int,int> (std::tr1::_Nil &,std::tr1::_Nil &)
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxbind0(10) : see reference to class temp late instantiation 'std::tr1::_Bind2<_Callable,_Arg0,_Arg1>::_Return<_Barg0,_Barg1,_Barg2,_Barg3,_Barg4,_B arg5,_Barg6,_Barg7,_Barg8,_Barg9>' being compiled
        with
        [
            _Callable=std::tr1::_Callable_obj<fopow<int,int>,false>,
            _Arg0=int,
            _Arg1=std::tr1::_Ph<1>,
            _Barg0=std::tr1::_Nil &,
            _Barg1=std::tr1::_Nil &,
            _Barg2=std::tr1::_Nil &,
            _Barg3=std::tr1::_Nil &,
            _Barg4=std::tr1::_Nil &,
            _Barg5=std::tr1::_Nil &,
            _Barg6=std::tr1::_Nil &,
            _Barg7=std::tr1::_Nil &,
            _Barg8=std::tr1::_Nil &,
            _Barg9=std::tr1::_Nil &
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\functional(408) : see reference to class template instantiation 'std::tr1::_Bind_base<_Ret,_BindN>' being compiled
        with
        [
            _Ret=std::tr1::_Notforced,
            _BindN=std::tr1::_Bind2<std::tr1::_Callable_obj<fopow<int,int>,false>,int,std::tr1::_Ph<1>>
        ]
        Test2.cpp(26) : see reference to class template instantiation 'std::tr1::_Bind_fty<_Fty,_Ret,_Bind N>' being compiled
        with
        [
            _Fty=fopow<int,int>,
            _Ret=std::tr1::_Notforced,
            _BindN=std::tr1::_Bind2<std::tr1::_Callable_obj<fopow<int,int>,false>,int,std::tr1::_Ph<1>>
        ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(28) : error C2039: 'result' : is not a m ember of 'fopow<BaseT,ExpT>'
        with
        [
            BaseT=int,
            ExpT=int
        ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(28) : error C2143: syntax error : missin g ';' before '<' C:\Program Files\Microsoft Visual Studio
10.0\VC\INCLUDE\xxresult(28) : error C4430: missing type specifie r - int assumed. Note: C++ does not support default-int C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(28) : error C2039: 'type' : is not a mem ber of '`global namespace'' C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(28) : error C2238: unexpected token(s) p receding ';' C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : error C2039: '_Type' : is not a me mber of 'std::tr1::_Result_type2<__formal,_Fty,_Arg0,_Arg1>'
        with
        [
            __formal=false,
            _Fty=fopow<int,int>,
            _Arg0=std::tr1::_Nil &,
            _Arg1=std::tr1::_Nil &
        ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : error C2146: syntax error : missin g ';' before identifier '_Type' C:\Program Files\Microsoft Visual Studio
10.0\VC\INCLUDE\xxresult(40) : error C4430: missing type specifie r - int assumed. Note: C++ does not support default-int C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : error C2602: 'std::tr1::_Result_of 2<_Fty,_Farg0,_Farg1>::_Type' is not a member of a base class of 'std::tr1::_Result_of2<_Fty,_Farg0,_Farg1
>'
        with
        [
            _Fty=fopow<int,int>,
            _Farg0=std::tr1::_Nil &,
            _Farg1=std::tr1::_Nil &
        ]
        C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : see declaration of 'std::t r1::_Result_of2<_Fty,_Farg0,_Farg1>::_Type'
        with
        [
            _Fty=fopow<int,int>,
            _Farg0=std::tr1::_Nil &,
            _Farg1=std::tr1::_Nil &
        ] C:\Program Files\Microsoft Visual Studio 10.0\VC\INCLUDE\xxresult(40) : error C2868: 'std::tr1::_Result_of 2<_Fty,_Farg0,_Farg1>::_Type' : illegal syntax for using-declaration; expected qualified-name
        with
        [
            _Fty=fopow<int,int>,
            _Farg0=std::tr1::_Nil &,
            _Farg1=std::tr1::_Nil &
        ]

我认为问题的根源是 bind() 或 transform() 但我不知道代码到底出了什么问题(因为它编译正常，没有 g++ 的单一警告)。有谁知道如何在不借助预处理器魔法的情况下修复我的代码？

Answer 1

std::bind在 VS2010 中不是您认为的那样:实际上是 std::tr1::bind ，并使用 std::tr1::result_of ，这比编译器辅助的 std::result_of 要弱得多C++11 标准强制要求。

特别是，不要尝试使用 std::bind在 VS10 中使用 lambda 表达式。

您可以在此处通过 fopow 解决此问题继承std::binary_function<BaseT, ExpT, BaseT> .