Thanks, Marc. Please consider this test code:
void f();
template <typename T> void foo(const T);
void Test()
{
foo(f);
}
int main(Test());
It compiles sucessfully for GCC 4.5. As you know, we are trying to add
cv-qualifier on top of function type while template deduce happens.
On Fri, Feb 18, 2011 at 11:38 PM, Marc Glisse <marc.glisse@xxxxxxxx> wrote:
> On Fri, 18 Feb 2011, Ian Lance Taylor wrote:
>
>> zhang qingshan <steven.zhang54373@xxxxxxxxx> writes:
>>
>>> /* ------- test case -------------------*/
>>> void x();
>>> template <typename T>
>>> void foo(const T*);
>>>
>>> int main() {
>>> foo(x);
>>> }
>>>
>>> GCC 4.5 complains:
>>>
>>> a.cpp: In function 'int main()':
>>> a.cpp:6: error: no matching function for call to 'foo(void (&)())'
>>>
>>> It seems that, const T * is resolved as void (&)());
>>>
>>> IMO, T --> void (), const T --> void (), const T * --> void (*)(), and
>>> it should be leagle.
>>
>> You are confusing function pointers with pointers to data objects. They
>> are not the same thing in C++. That is, a function pointer is not a
>> special type of pointer.
>
> Well it still kind of is. Without the "const", the code compiles fine. But
> the fact that a const qualifier on a function type is ignored seems not to
> apply to template type deduction.
>
> (note that most compilers behave like g++ here, except for clang which
> accepts the original code)
>
> --
> Marc Glisse
>
Consider this test case:
void f();
template <typename T> foo(const T&);
void Test()
{
foo(f);
}
