g++ error I can't figure out

[Mardok45]

Before I start posting snippets of my code, does anyone happed to know what this error means:

Request for member 'function name' in 'class name', which is of non-class type.

[aks44]

You tried to call "function name" on an object of type "class name" but you messed up somewhere because "class name" is not a class (is it a builtin-type??).

Better post some code...

[Mardok45]

This is my OBJLoader header file:

class OBJLoader
{
public:
OBJLoader();
~OBJLoader();
bool load(char *file);
void render();

private:
std::fstream file;

std::vector<face*> faces;
std::vector<texture*> textures;
std::vector<vertex*> vertices;

void readLine(std::string&);

void readFace(std::string);
void readVertex(std::string);
void readTexture(std::string);
};

Now we jump over to my main file:

OBJLoader cube();

int main(int argc, char** argv)
{
cube.load("cube.obj");//request for member ‘load’ in ‘cube’, which is of non-class type ‘OBJLoader ()()’

return 0;
}

There's like 90 lines of code in my main function and 200+ lines in my OBJLoader defining the functions, which is why I don't want to post my code :\
Plus, I compiled this in Dev-C++ and Visual Studio in Windows and it all compiled fine...

[aks44]

OBJLoader cube();

The compiler sees that as a forward-declaration of a function (function cube which takes no arguments and returns an instance of OBJLoader) rather than a variable definition (variable cube of type OBJLoader that uses the default constructor).

Since you're using the default constructor, just ditch the parenthesis and you'll be fine:


OBJLoader cube;


EDIT: Note: this ambiguity doesn't happen with anything else than the default constructor, since the compiler is then able to tell the difference between a function declaration and a variable definition, eg:

OBJLoader cube(TypeName paramName); // forward-declaration of a function, takes 1 param of type TypeName and returns an OBJLoader instance
OBJLoader cube(TypeName); // same here, since the compiler can resolve TypeName to a type name

versus

OBJLoader cube(argument); // variable definition, type OBJLoader using a custom constructor (since the compiler can resolve argument to some other variable)


EDIT again:

Plus, I compiled this in Dev-C++ and Visual Studio in Windows and it all compiled fine...
Visual Studio is not a reference when it comes to standards correctness (dunno about Dev-C++, but it seems it made the same error). g++ is right on this one, the C++ standard mandates that behaviour (although I won't bother to search & quote chapter and verse).

[gnusci]

Very funny... ;)


You tried to call "function name" on an object of type "class name" but you messed up somewhere because "class name" is not a class (is it a builtin-type??).

Better post some code...

ok here is my answer, you have to pay attention to the important changes I also did some modifications to be able to compile it, here it is:




using namespace std;

class OBJLoader
{
public:
OBJLoader(){};
~OBJLoader(){};

bool load(char *file); //<------ file
void render();

private:

fstream file; //<------ file

vector<face*> faces;
vector<texture*> textures;
vector<vertex*> vertices;

void readLine(string&);

void readFace(string);
void readVertex(string);
void readTexture(string);
};


OBJLoader cube; //<------ without "()"

int main(int argc, char** argv)
{
cube.load("cube.obj"); //I get the error here
return 0;
}

[aks44]

@gnusci:

1. good point about the file (argument) vs file (member) name clash. I didn't notice it at first glance. :) I guess it's just another reason to stick to strict naming schemes (as far as I'm concerned, all data members start with m_ )

2. for once that someone doesn't use using namespace, please, I beg you, please don't give him/her bad habits. using namespace is one of the very few features (the only one I can think of ATM) that really should be removed from the language, it totally denies the benefits of namespaces...