Function definition to use across project Visual C++

Question

Trying to start up again with Visual C++, using 2010 Express edition.

Trying to figure out something.

If define a function in the Project.cpp file, why can't I use it in the Form1.h file, specifically the private: System::Void Form1_Load?

I get this error:

1>c:\users\boss\documents\visual studio 2010\projects\second\second\Form1.h(94): error C3861: 'Function': identifier not found

Is there any way to define a function so it can be used anywhere?

in Form1.h:

private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {
    this->txtMain->Text += FunctionX("Data");
    this->txtMain->SelectionStart = this->txtMain->Text->Length;
}

in Project.cpp:

std::string FunctionX(std::string message) {
    // other code here
    return message;
}

It looks like you are missing a forward declaration and a marshal_as for the native to CLI conversion — Niall, Sep 07 '15 at 18:29
I changed the project properties from /cls:pure to /clr, everything else works fine. if I change it to no clr support, I get 50 other errors. — Wyllow Wulf, Sep 07 '15 at 18:31
Where would I forward declare? I Put "std::string FunctionX(std::string message)" in Form1.h, resulting in a dozen different errors. — Wyllow Wulf, Sep 07 '15 at 18:48

score 0 · Accepted Answer · answered Sep 07 '15 at 19:06

private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {
extern std::string FunctionX(std::string message);
this->txtMain->Text += msclr::interop::marshal_as<System::String^>(FunctionX("Data"));
this->txtMain->SelectionStart = this->txtMain->Text->Length;
}

This works! Thanks for the tips.

Function definition to use across project Visual C++

1 Answers1