[Bug c++/5458] address of overloaded template function as argument for template

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2006-08-21 17:13 -------
*** Bug 28793 has been marked as a duplicate of this bug. ***


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pinskia at gcc dot gnu dot org changed:

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                 CC|                            |suzev dot kirill at gmail
                   |                            |dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[v dot haisman at sh dot cvut dot cz]

------- Comment #10 from v dot haisman at sh dot cvut dot cz  2006-10-09 14:16 -------
Shouldn't the "Known to fail" field get all the versions from its duplicates
copied? Maybe that is why this rejects-valid bug is still not fixed even though
most other rejects-valid bugs get a lot of attention and get fixed usually
pretty fast, IMHO.

2.95.3 3.0.4 4.0.0 4.1.0 4.2.0 3.3.3 3.2.3


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Comment #11 from pinskia at gcc dot gnu dot org  2007-08-06 13:58 -------
*** Bug 33004 has been marked as a duplicate of this bug. ***


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pinskia at gcc dot gnu dot org changed:

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                 CC|                            |rodolfo at rodsoft dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[rodolfo at rodsoft dot org]

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------- Comment #12 from rodolfo at rodsoft dot org  2007-08-06 14:18 -------
This is an yet simpler case where this bug shows up:

template <class T> void foo(T);
void foo(int);

void bar()
{
    &foo;
}

i686-pc-linux-gnu-g++-4.2.1 fails with:

teste.cpp: In function ‘void bar()’:
teste.cpp:6: error: statement cannot resolve address of overloaded function


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[v dot haisman at sh dot cvut dot cz]

------- Comment #13 from v dot haisman at sh dot cvut dot cz  2008-01-07 20:47 -------
This still fails in 4.3.0. Know to fail sorted and without duplicates should
read: 2.95.3 3.0.4 3.2.3 3.3.3 4.0.0 4.1.0 4.2.0 4.3.0


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[jason at gcc dot gnu dot org]

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------- Comment #14 from jason at gcc dot gnu dot org  2009-11-25 02:55 -------
I'm not sure the standard actually says that this is well-formed, though it
seems reasonable to me.

13.4/2: If the name is a function template, template argument deduction is done
(14.9.2.2), and if the argument deduction succeeds, the resulting template
argument list is used to generate a single function template specialization,
which is added to the set of overloaded functions considered.

14.9.2.2: The function template’s function type and the specified type are used
as the types of P and A, and the deduction is done as described in 14.9.2.5.

It's not entirely clear that there is a "specified type" for this kind of
two-way deduction.  EDG also rejects this.


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jason at gcc dot gnu dot org changed:

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                 CC|                            |jason at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[joseph dot h dot garvin at gmail dot com]

------- Comment #15 from joseph dot h dot garvin at gmail dot com  2010-01-21 18:38 -------
I'm not sure what the standard says, but conceptually, if you only provide a
template generic template foo, with no non-templated foo defined, then
instantiations of foo are *never* 'overloaded.' If I have:

template<int n>
void foo() {}

Then foo<3> is a distinct function from foo<2>. It doesn't make sense to refer
to foo as overloaded (unless there is also a non-templated foo defined). foo<3>
has a single unique address, there is no ambiguity. Automatically considering
it an overloaded function (as I suspect GCC must be doing internally) leads to
a confusing error when compiling this snippet:

#include <iostream>

template<int n>
void foo() {}

int main()
{
        &foo;
}

You get the same error about not being able to resolve foo because it's
overloaded. But foo isn't a function at this point. It's a template. And no
template parameters have been filled in. I should get an error about expecting
angle brackets.


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joseph dot h dot garvin at gmail dot com changed:

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                 CC|                            |joseph dot h dot garvin at
                   |                            |gmail dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[jwakely dot gcc at gmail dot com]

------- Comment #16 from jwakely dot gcc at gmail dot com  2010-01-21 19:00 -------
Shouldn't it get the same error as for this case?

template<class T>
T foo() { return T(); }

int main()
{
        &foo;
}

That example can be made valid like so:

        int (*pf)() = &foo;

Which demonstrates that the angle brackets are not necessary, *if* the compiler
can determine which specialisation is intended.  So the "cannot resolve address
of overloaded function" error is arguably correct.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[jason at gcc dot gnu dot org]

------- Comment #17 from jason at gcc dot gnu dot org  2010-01-21 19:09 -------
We describe a template as overloading itself since it represents any number of
actual functions.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-09-26 20:56 -------
*** Bug 17683 has been marked as a duplicate of this bug. ***

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                 CC|                            |v dot haisman at sh dot cvut
                   |                            |dot cz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-08-27 13:27 -------
*** Bug 17208 has been marked as a duplicate of this bug. ***

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                 CC|                            |igodard at pacbell dot net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-08-18 12:58 -------
PR 17071 has this very nice and clean testcase.  
-------------- 
int foo (int); 
template <class T> T foo (T, T); 
 
template <class T, class U> int bar (T, U); 
 
int main () 
{ 
    bar (0, &foo); 
} 
--------------------- 
 
W.  

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-18 02:23 -------
*** Bug 17071 has been marked as a duplicate of this bug. ***

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                 CC|                            |sebor at roguewave dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-15 21:27 -------
*** Bug 15469 has been marked as a duplicate of this bug. ***

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                 CC|                            |relf at os2 dot ru


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-31 19:08 -------
*** Bug 13947 has been marked as a duplicate of this bug. ***

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                 CC|                            |debian-gcc at lists dot
                   |                            |debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458

[Bug c++/5458] address of overloaded template function as argument for template

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-31 19:06 -------
Here is a simple testcase:
template <class T> class vector{};
template <class T> vector <T> foo(vector <T>) {}
void foo(int) {}
float foo(float) {}
template <class T_arg, class T_result>
void ptr_fun(T_result (*f)(T_arg)) {}
main() { ptr_fun<float>(foo);   }

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5458