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Problems with 'const'

5 posts in this topic

I am having problems with making a registered object obey constness. In the following example, when compiling the script it reports the float assignment as an error due to g_float being const but it doesn't complain about the assignment of g_object. Any suggestions to what I am doing wrong? Cheers. Host App
engine->RegisterGlobalProperty("const TestObject g_object", &g_object);
engine->RegisterGlobalProperty("const float g_float", &g_float);
TestObject	myObject;
float		myFloat;

void Init()
	g_object = myObject;
	g_float = myFloat;


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I made the following test and it worked as expected:

// Tests constant properties to see if they can be overwritten
// Test author: Andreas Jonsson

#include "angelscript.h"
#include <stdio.h>
#include <stddef.h>
#include <string.h>

#define TESTNAME "TestConstProperty"

class COutStream : public asIOutputStream
void AS_CALL Write(const char *text) { printf(text); }

static const char *script =
"Obj myObj; \n"
"float myFloat; \n"
" \n"
"void Init() \n"
"{ \n"
" g_Obj = myObj; \n"
" g_Float = myFloat; \n"
"} \n";

bool TestConstProperty()
bool fail = false;

asIScriptEngine *engine = asCreateScriptEngine(ANGELSCRIPT_VERSION);

engine->RegisterObjectType("Obj", sizeof(int), asOBJ_PRIMITIVE);
engine->RegisterObjectProperty("Obj", "int val", 0);

int constantProperty = 0;
engine->RegisterGlobalProperty("const Obj g_Obj", &constantProperty);

float constantFloat = 0;
engine->RegisterGlobalProperty("const float g_Float", &constantFloat);

COutStream out;
engine->AddScriptSection(0, TESTNAME, script, strlen(script));
engine->Build(0, &out);


// Success
return fail;

The output was:

TestConstProperty (6, 9) : Error : Reference is read-only
TestConstProperty (7, 11) : Error : Reference is read-only

Note this was made with 1.9.0 WIP 2, which is not yet released. However, I haven't made any changes that I know of in the way constants are treated or the way properties are registered.

Can you verify the problem once more for me?

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Thanks for looking into it.

I have investigated the problem further and it only seems to ignore the 'const'ness if you declare you own asBEHAVE_ASSIGNMENT function on the object.

I have also tried it on the bstr and that doesn't seem to work either.

I am using 1.9.0 WIP 1.

Hope that helps.


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You were right. When registering the asBEHAVE_ASSIGNMENT function the compiler doesn't check if the variable is const or not.

I'll have this fixed for the next release.

I would like to credit you for finding the bug, but I don't know your name. Would you mind telling me?

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