Function define inside chaiscript and arguments cast #303
Description
- Compiler Used: MSVC13
- Operating System: Windows 7
- Architecture (ARM/x86/32bit/64bit/etc): 64bit
There is a different of treatment with arguments casting between c++ function called with chaiscript, and chaiscript function.
With C++ there is a boxed_cast for each argument in order to make match provided arguments and required arguments. (call_func in proxy_functions_detail.hpp:219)
With Chaiscript function there isn't any boxed_cast so if argument doesn't perfectly match an eval_error is raised (match in proxy_functions.hpp:110)
Here is an example :
#include <chaiscript/chaiscript.hpp>
#include <chaiscript/utility/utility.hpp>
#include <chaiscript/chaiscript_stdlib.hpp>
#include <iostream>
class A
{
public:
A() {}
virtual ~A() {}
};
class B : public A
{
public:
B() : A() {}
virtual ~B() {}
};
int main(int ac, char** av)
{
chaiscript::ChaiScript chai(chaiscript::Std_Lib::library());
//-------------------------------------------------------------------------
chai.add(chaiscript::user_type<A>(), "A");
chai.add(chaiscript::user_type<B>(), "B");
chai.add(chaiscript::base_class<A, B>());
chai.add(chaiscript::fun([](const B * test)
{
std::cout << "ok" << std::endl;
}), "CppFunctWithBArg");
chai.add(chaiscript::fun([]() -> A*
{
return ((A*) new B());
}), "Create");
try
{
chai.eval(R"(
var inst = Create() // A*
// it prints "A"
inst.type_name().print()
// Ok it is casted using conversion
CppFunctWithBArg(inst)
// Define a function with B as argument
def ChaiFuncWithBArg(B inst)
{
print("ok")
}
// don't work
ChaiFuncWithBArg(inst)
)");
}
catch (chaiscript::exception::eval_error e)
{
std::cout << e.what() << std::endl;
std::cout << e.pretty_print() << std::endl;
}
catch (std::exception e)
{
std::cout << e.what() << std::endl;
}
}
Output is :
A
ok
Error: "Guard evaluation failed with function 'ChaiFuncWithBArg'"
Error: "Guard evaluation failed with function 'ChaiFuncWithBArg'" during evaluation at (__EVAL__ 17, 3)
__EVAL__ (17, 3) 'ChaiFuncWithBArg(inst)'
Thank you for reading !