[Bug c++/45501] New: Compiler does not find template function if member is addressed with "this"

[Bug c++/45501] New: Compiler does not find template function if member is addressed with "this"

[grottel at vis dot uni-stuttgart dot de]

Command line:
g++ -o File.o File.cpp

Testes with gcc 4.5.0 and 4.3.1

Content of .cpp-file:
#include <cstdio>

template<class T>
class MetaObj {
public:
    const char *GetText(void) const {
        return T::GetTextStatic();
    }
};

class Obj {
public:
    static const char *GetTextStatic(void) {
        return "Text";
    }
};

class Printer {
public:
    void PrintText(const char *who, const char *what) {
        printf("%s: %s\n", who, what);
    }
    template<class T> void PrintTextFrom(void) {
        T *d = new T();
        PrintText("Printer-Meta", d->GetText());
        delete d;
    }
};

template<unsigned int CNT>
class MultiInfoPrinter {
public:
    MultiInfoPrinter(void) {
        for (unsigned int i = 0; i < CNT; i++) {
            this->prn.PrintText("MultiInfoPrinter-Static",
Obj::GetTextStatic());   // works
            this->prn.PrintText("MultiInfoPrinter-Meta",
MetaObj<Obj>().GetText()); // works
            prn.PrintTextFrom< MetaObj<Obj> >();                               
    // works
            this->prn.PrintTextFrom< MetaObj<Obj> >();                         
    // WORKS NOT with gcc, but with icc!!! WHY???
        }
    }
private:
    Printer prn;
};

int main(int argc, char *argv[]) {
    MultiInfoPrinter<2> p;
}


-- 
           Summary: Compiler does not find template function if member is
                    addressed with "this"
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: grottel at vis dot uni-stuttgart dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45501

[Bug c++/45501] Compiler does not find template function if member is addressed with "this"

[paolo dot carlini at oracle dot com]

------- Comment #1 from paolo dot carlini at oracle dot com  2010-09-02 17:16 -------
Since PrintTextFrom is a template, you can (should) write:

  this->prn.template PrintTextFrom< MetaObj<Obj> >();

which works with both compilers. Since apparently ICC 11.1 likes in strict mode
also the form without 'template' let's ask Jason if we are right in rejecting
it (while accepting it without this->)


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45501

[Bug c++/45501] Compiler does not find template function if member is addressed with "this"

[paolo dot carlini at oracle dot com]

------- Comment #2 from paolo dot carlini at oracle dot com  2010-09-02 17:44 -------
As a matter of fact, basing on my rough understanding of '.template', GCC may
well be correct: my rule of thumb is that 'template' is required when the
construct before the period depends on a template parameter: by itself prn,
being a Printer, doesn't; this->prn does, because this points to a
MultiInfoPrinter.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45501

[Bug c++/45501] Compiler does not find template function if member is addressed with "this"

[jason at gcc dot gnu dot org]

------- Comment #3 from jason at gcc dot gnu dot org  2010-09-03 01:36 -------
prn and this->prn are equivalent.  Specifically, the type of *this is the
current scope, so although it is a dependent type it is not a dependent scope
and .template should not be needed.


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2010-09-03 01:36:05
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45501

[Bug c++/45501] Compiler does not find template function if member is addressed with "this"

[paolo dot carlini at oracle dot com]

------- Comment #4 from paolo dot carlini at oracle dot com  2010-09-03 09:09 -------
Ah, ok, thanks Jason.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45501