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bug? setter with string

Started by Takayuki Feb 15, 2010 at 12:41 PM 6 replies 1.8k views

Original Post

Feb 15, 2010 at 12:41 PM

Because it might be a bug, it reports. The following error occurs and the setter doesn't operate correctly. "The property 'FileName' has mismatching types for the get and set accessors" ////////// CMyClass ////////// // static void CMyClass::set_FileName_Generic(asIScriptGeneric *gen) { ..... } void CMyClass::set_FileName(const std::string &strText) { ..... } ////////// Register type1 ////////// r = engine->RegisterObjectMethod("CMyClass", "void set_FileName(const string ∈)", asFUNCTION(CMyClass::set_FileName_Generic), asCALL_GENERIC); assert(r>=0); ////////// Registertype2 ////////// r = engine->RegisterObjectMethod("CMyClass", "void set_FileName(const string ∈)", asMETHODPR(CMyClass, set_FileName, (const std::string &), void), asCALL_THISCALL); assert(r>=0); ////////// Script typeA ////////// // Register type1 OK // Register type2 OK CMyClass my; my.set_FileName("c:\\test.txt"); ////////// Script typeB ////////// // Register type1 Error // Register type2 Error CMyClass my; my.FileName = "c:\\test.txt";

WitchLord

Feb 15, 2010 at 3:52 PM

Thanks for the report. I'll take a look at this.

Are you registering the 'get_FileName' method as well? If so, how is it registered?

Takayuki

Feb 15, 2010 at 5:41 PM

Hello.
The problem was not in 'Get_FileName'.

WitchLord

Feb 16, 2010 at 12:36 PM

I'm sorry, did you mean that you didn't register the 'get_FileName'?

I tried reproducing this problem, but I'm not getting the compile error you mentioned.

That error should only happen if both the set and get property accessors are there, but they have a different type, e.g. 'int get_FileName()' and 'void set_FileName(const string ∈)'.

Regards,
Andreas

Takayuki

Feb 17, 2010 at 12:37 AM

My get_FileName was registered like this.

////////// CMyClass //////////
CScriptString *get_FileName()
{
/* */CScriptString *pstr = new CScriptString();
.....
/* */return pstr;
}

////////// Register type //////////
r = engine->RegisterObjectMethod("CMyClass", "string@ get_FileName()", asMETHOD(CMyClass, get_FileName), asCALL_THISCALL);

WitchLord

Feb 17, 2010 at 6:20 AM

OK. Then I know why you get the error:

void set_FileName(const string ∈) and string@ get_FileName() is not using the same type. One is using 'string' and the other is using 'string@', that's why the compiler is giving the error.

Since you can't change the get_FileName to return a reference, without getting a memory leak, I suggest you change set_FileName to take a string handle instead, i.e. void set_FileName(string@).

From my side, I will also look into changing the compiler to allow this difference in types, since both are really the same base object.

Regards,
Andreas

Takayuki

Feb 18, 2010 at 1:04 AM

For the reference.
"get_FileName" seems to be called internally though "void set_FileName(string@)" was tried.

my.FileName = "c:\\test.txt"; // C++ call get_FileName

WitchLord

Feb 18, 2010 at 7:30 AM

Hmm. I'll have to think how this should best be solved.

What's happening is this. The compiler sees that you're attempting to do a value assignment, but it understands that the property is a handle. Thus the code is rewritten as follows:

string @tmp = @my.get_FileName();tmp = "c:\\test.txt";

If the script was written as @my.FileName = @"c:\\test.txt"; then the compiler would call set_FileName instead. But I understand that you do not want to force the script to do a handle assignment.

I need to change AngelScript so that the application can inform that the property is not a handle, yet still allow the get accessor to return a handle instead of a reference in order to avoid memory leaks.

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