Taking member function pointer

[ihnorton]

To make the Qt example nicer, I tried this:
setup(hibtn, @cxx(&QPushButton::clicked))
which fails with:

cpp_ref: cxxref(CppAddr((CppNNS{(:QPushButton,:clicked)})()))
cxxref: CppAddr{CppNNS{(:QPushButton,:clicked)}}
:1:1: error: must explicitly qualify name of member function when taking its address
^
QAbstractButton::
ERROR: `juliatype` has no method matching juliatype(::CppPtr{CppValue{CppBaseType{symbol("clang::Type")},(false,false,false)},(false,false,false)})
while loading /home/isaiah/.julia/Cxx/test/qt1.jl, in expression starting on line 80

and this
setup(hibtn, pcpp"QPushButton::clicked"), which fails with:

jldev: /cmn/jldev/deps/llvm-svn/tools/clang/lib/Frontend/../../include/clang/AST/Type.h:562: const clang::ExtQualsTypeCommonBase* clang::QualType::getCommonPtr() const: Assertion `!isNull() && "Cannot retrieve a NULL type pointer"' failed.

signal (6): Aborted

Is there a way to do this that I am missing?

[Keno]

The first way should work.

[maxruby]

@ihnorton. FWIW, I think it works if you do the following:

# Passing a message to the Julia REPL (Fix)
# Create a function that prints a message in the REPL
say_hi() = println("Hi, this is fun!")::Void

. . . (same as before)

# Setup the button so that it is responsive to the click
cxx"""
   void setup(QPushButton* hibtn) 
   {
       QObject::connect(hibtn, &QPushButton::clicked, handle_hi);
   }
"""
@cxx setup(hibtn)

. . . (same as before)

# execute the app
@cxx app->exec()

Output

. . . last step
julia>  @cxx app->exec()        # click button "say hi" 
Hi, this is fun!

The current implementation in test/qttest.jlfreezes and does not seem to work, i.e., button is completely unresponsive. QMessageBoxwill remain unresponsive until you run @cxx app->exec().
(Note also you don´t need to add #include<iostream> in the cxx declaration of void handle_hi()).

[ihnorton]

@maxruby thanks - the version currently on master does work for me. However, I'm trying to to write a generalized connect function which is able to take an arbitrary signal.

[maxruby]

Sorry this was not helpful at all . . . I also have Cxx master and actually copied the code straight from Github to be 100% sure. Unfortunately, it hangs and I can not click the button at all.

[ihnorton]

@maxruby no worries, it will be good to make sure it works on other plaforms (I'm on linux).

@Keno I thought it ought to work too. But the error is from bootstrap.cpp::createAddrOfExpr receiving the following expression (I added expr->dump() and res = CreateBuiltinUnaryOp...; res->dump())

input expression:

DeclRefExpr 0x6cdf4b0 'void (_Bool)' CXXMethod 0x6cb5180 'clicked' 'void (_Bool)'

result expression (after the error :1:1: error: must explicitly qualify name of member function when taking its address)

QAbstractButton::
UnaryOperator 0x1c4850d0 'void (class QAbstractButton::*)(_Bool)' prefix '&'
`-DeclRefExpr 0x1c485060 'void (_Bool)' CXXMethod 0x1c45adf0 'clicked' 'void (_Bool)'

Kind of confusing that the resulting expression does appear to be properly qualified despite the error message.

[Keno]

I can take a look in a bit as soon as a I figure out #53, which I'm currently working on.

[maxruby]

@ihnorton. OK. I will just use my own version of qttest.jl with a code that works for my system. If others have the same problem with OSX 10.9 or Mac in the future, at least they are informed in #57 (until it is fixed).

[ihnorton]

@Keno the issue here appears to be (at least in part):

• in bootstrap.cpp:CreateDeclRefExpr there is no qualifier in the resulting NestedNameSpecifierLoc from this call:

(gdb) f
#0  CreateDeclRefExpr (D=0x76ccbb0, builder=0x3971d40, islvalue=0) at ../src/bootstrap.cpp:832
832     clang::QualType T = D->getType();
(gdb) p builder->getWithLocInContext(*clang_astcontext)
$42 = {Qualifier = 0x0, Data = 0x0}

• I believe this is because in declfornns the nnsbuilder is dropped once the inner decl is reached:
  https://github.com/Keno/Cxx.jl/blob/625be3218dac65387ecd3ede59134cd81b28f053/src/Cxx.jl#L1165
• if I change that line to always pass nnsbuilder, then the must explicitly qualify name error goes away. (I still get the juliatype has no method... one though).

[Keno]

Yes, I have reached the same conclusion. Patch on its way.

[ihnorton]

The member reference error is definitely fixed, but now I get:

julia> x = @cxx(&QPushButton::clicked);
ERROR: `convert` has no method matching convert(::Type{CppPtr{CppValue{CppBaseType{symbol("clang::Type")},(false,false,false)},(false,false,false)}}, ::QualType)
Closest candidates are:
  convert(::Type{T}, ::T)
  convert(::Type{Nullable{T}}, ::T)

 in anonymous at ./REPL.jl

This doesn't seem like a display issue, because x is not defined afterward. Any suggestions where to look?

[Keno]

Fixed!