Build error after commit e033ffcc21

[eivindro]

I get this build error on windows/mingw compiler after commit e033ffcc21

In file included from .\all.cpp:2:0:
.\cpp/capi.cpp: In function 'void windowShow(QQuickWindow_*)':
.\cpp/capi.cpp:178:22: error: expected type-specifier before 'ShowWindow'
     reinterpret_cast<ShowWindow *>(win)->show();
                      ^
.\cpp/capi.cpp:178:22: error: expected '>' before 'ShowWindow'
.\cpp/capi.cpp:178:22: error: expected '(' before 'ShowWindow'
.\cpp/capi.cpp:178:34: error: expected primary-expression before '>' token
     reinterpret_cast<ShowWindow *>(win)->show();
                                  ^
.\cpp/capi.cpp:178:40: error: 'QQuickWindow_* {aka void*}' is not a pointer-to-object type
     reinterpret_cast<ShowWindow *>(win)->show();
                                        ^
.\cpp/capi.cpp:178:48: error: expected ')' before ';' token
     reinterpret_cast<ShowWindow *>(win)->show();
                                                ^

[niemeyer]

Please see if the latest push to tip helps.

[radisson]

Trying to get it working on Windows. Same results than original poster with the latest push.

[niemeyer]

Is that the full error or is there any other warning before that?

[eivindro]

Got it!

Turns out one has to write class in front of ShowWindow, like so:

    reinterpret_cast<class ShowWindow *>(win)->show();

This is probably because there is a global function called ShowWindow defined in the Win32 API which naturally is available when using mingw, I have to admit that ShowWindow is an extraordinary bad name for a class (it sounds like a function), it just shows that you have to be careful when naming variables in C/C++ even when they're internal.

[niemeyer]

To me it shows that C++ is extraordinarily bad at namespacing and error reporting.

Thanks for figuring it out.

[oblitum]

Maybe a case for blaming the compiler instead. In the past, building Qt with clang I got trivial errors that go unnoticed with g++ (let's not even talk about msvc). I got better error messages and it even provided fix suggestions...

[oblitum]

just to compare

code

void x(){}
struct x{};

int main()
{
    reinterpret_cast<x *>(0);
}

clang 3.4

francisco@Ubuntu:~/Projetos/samples$ clang++ sample.cpp
sample.cpp:6:22: error: must use 'struct' tag to refer to type 'x' in this scope
    reinterpret_cast<x *>(0);
                     ^
                     struct 
sample.cpp:1:6: note: struct 'x' is hidden by a non-type declaration of 'x' here
void x(){}
     ^
sample.cpp:6:5: warning: expression result unused [-Wunused-value]
    reinterpret_cast<x *>(0);
    ^~~~~~~~~~~~~~~~~~~~~~~~
1 warning and 1 error generated.

gcc 4.8

francisco@Ubuntu:~/Projetos/samples$ g++ sample.cpp 
sample.cpp: In function ‘int main()’:
sample.cpp:6:22: error: expected type-specifier before ‘x’
     reinterpret_cast<x *>(0);
                      ^
sample.cpp:6:22: error: expected ‘>’ before ‘x’
sample.cpp:6:22: error: expected ‘(’ before ‘x’
sample.cpp:6:25: error: expected primary-expression before ‘>’ token
     reinterpret_cast<x *>(0);
                         ^
sample.cpp:6:29: error: expected ‘)’ before ‘;’ token
     reinterpret_cast<x *>(0);
                             ^