#define class struct
#define protected public
#define private public

#include "imported.h"

#undef class 
#undef protected 
#undef private

C>>в работе я такое не использую, а вот эксперимент поставил... И все работает корректно

template<class A> ...

C>я никаких пунктов стандарта не нарушаю?

C>#define class struct
C>#define protected public
C>#define private public

C>#include "imported.h"

C>#undef class 
C>#undef protected 
C>#undef private 
C>

A translation unit that includes a header shall not contain any macros that define names declared or defined in that header. Nor shall such a translation unit define macros for names lexically identical to keywords.

C>честно почитал, но проблему не нашел... ткните носом

class MyClass
{
protected:
    // GCC mangling: _ZN7MyClass11doSomethingEv
    // MSVC mangling: ?doSomething@MyClass@@IAAXXZ
    void doSomething();
};

class MyClass
{
public:
    // GCC mangling: _ZN7MyClass11doSomethingEv (unchanged)
    // MSVC mangling: ?doSomething@MyClass@@QAAXXZ
    void doSomething();
};

C>>честно почитал, но проблему не нашел... ткните носом

_>class MyClass
_>{
_>protected:
_>    // GCC mangling: _ZN7MyClass11doSomethingEv
_>    // MSVC mangling: ?doSomething@MyClass@@IAAXXZ
_>    void doSomething();
_>};

_>class MyClass
_>{
_>public:
_>    // GCC mangling: _ZN7MyClass11doSomethingEv (unchanged)
_>    // MSVC mangling: ?doSomething@MyClass@@QAAXXZ
_>    void doSomething();
_>};
_>

#pragma comment(lib, "importedProject.lib")

class MyClass
{
protected:
    void doSomething();
};

#include "a.h"
#include <iostream>

void MyClass::doSomething()
{
    std::cout<<"It works!!!"<<std::endl;
}

#define protected public
#include "a.h"
#undef protected

int main()
{
    MyClass a;
    a.doSomething();
}

1>b.obj : error LNK2019: unresolved external symbol "public: void __thiscall MyClass::doSomething(void)" (?doSomething@MyClass@@QAEXXZ) referenced in function _main

b.obj : error LNK2019: unresolved external symbol "public: void __thiscall MyClass::doSomething(void)" (?doSomething@MyClass@@QAEXXZ) referenced in function _main