functor parameter problem

hi i have a problem.

Quote:

---

error: no matching function for call to `test1(int&, int)'

---

Code:

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namespace test0 {

        template<typename test10, typename test11>
        const bool test1(bool&, const test10&, const test11&)
        {
                return(true);
        }
}

                template<typename test10, typename test11, typename test12>
                const bool test1(test10&, const test11&, const test12& = test0::test1)
                {
            return(false);
                }

int main(void)
{
    int x = 0;
    test1(x, 0);
}

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i dont know why functor wrong.

do anyonje know its kind of urgent

Your test1 template takes three concrete (non-default) arguments. You are instantiating the template using only two arguments.

Code:

---

template<typename test10, typename test11, typename test12>
bool test1(test10&, const test11&, const test12& = test0::test1)
{
}

int main(void)
{
    int x = 0;
    test1(x, 0, true);  // this works
}

---

This compiles fine with Comeau.

Regards,

What is the third parameter intended to be used for?

Yep, template argument deduction on the second test1 overload can't be complete as test12 can't be deduced.

i would rather hear a solution.

i have tried this:

Code:

---

    struct
    {
        template<typename test10, typename test11>
        const bool operator()(bool& x, const test10& y , const test11& z) const
        {
            return(x = true);
        }
    } test1;

                template<typename test10, typename test11, typename test12>
                const bool test2(test10& x, const test11& y, const test12& z = test1)
                {
                    bool a;
                    z(a, x, y);
            return(a);
                }

int main(void)
{
    int x = 0;
    test2(x, 0, test1);
}

---

it should be able to deduce test12 now but still no match.

Quote:

---

Originally Posted by Mitsukai

i would rather hear a solution.

---

So what do you call what I posted using your original code? There were no compilation errors in the example I posted if you specify the last parameter when the template is instantiated.

Now you've changed the code to a totally different example that doesn't compile for an entirely different set of reasons:

Quote:

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Thank you for testing your code with Comeau C/C++!
Tell others about http://www.comeaucomputing.com/tryitout !

Your Comeau C/C++ test results are as follows:

Comeau C/C++ 4.3.8 (Aug 19 2006 13:36:48) for ONLINE_EVALUATION_Alpha1
Copyright 1988-2006 Comeau Computing. All rights reserved.
MODE:strict errors C++

"ComeauTest.c", line 4: warning: type qualifier on return type is meaningless
const bool operator()(bool& x, const test10& y , const test11& z) const
^

"ComeauTest.c", line 8: error: use of a type with no linkage to declare a variable
with linkage
} test1;
^

"ComeauTest.c", line 11: warning: type qualifier on return type is meaningless
const bool test2(test10& x, const test11& y, const test12& z = test1)
^

"ComeauTest.c", line 21: error: a template argument may not reference an unnamed
type
test2(x, 0, test1);
^

2 errors detected in the compilation of "ComeauTest.c".

In strict mode, with -tused, Compile failed

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Code:

---

struct test1
{
    template<typename test10, typename test11>
    bool operator()(bool& x, const test10& y , const test11& z) const
    {
          return(x = true);
    }
};

test1 test_inst;

template<typename test10, typename test11, typename test12>
bool test2(test10& x, const test11& y, const test12& z = test_inst)
{
  bool a;
  z(a, x, y);
  return(a);
}

int main(void)
{
    int x = 0;
    test2(x, 0, test_inst);
}

---

This compiles fine.

Regards,

Paul McKenzie

but this does not .

Code:

---

    struct test1t
    {
        template<typename test10, typename test11>
        const bool operator()(bool& x, const test10& y , const test11& z) const
        {
            return(x = true);
        }
    };

    test1t test1;

                template<typename test10, typename test11, typename test12>
                const bool test2(test10& x, const test11& y, const test12& z = test1)
                {
                    bool a;
                    z(a, x, y);
            return(a);
                }

int main(void)
{
    int x = 0;
    test2(x, 0);
}

---

It doesn't compile for the same reasons as the first example.

Regards,

Paul McKenzie