c++/9887: Syntax error on explicit member function template argument in function template body

c++/9887: Syntax error on explicit member function template argument in function template body

[isak]

>Number:         9887
>Category:       c++
>Synopsis:       Syntax error on explicit member function template argument in function template body
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          rejects-legal
>Submitter-Id:   net
>Arrival-Date:   Fri Feb 28 14:06:00 UTC 2003
>Closed-Date:
>Last-Modified:
>Originator:     Isak Johnsson
>Release:        GNU C++ version 3.2.3 20030210
>Organization:
>Environment:
Debian GNU/Linux unstable on Intel Celeron machine with 256MB RAM.
>Description:
The type of a member funtion template can't be specified explicitly when called from the context of a funtion template where the class of the member function is a template argument. G++ gives a syntax error.

Preprocessed source:
# 1 "t.cc"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "t.cc"
class A {
public:
  template<typename V>
  void f() {
  }
};

template<typename T>
void g(T x) {
  x.f<int>(); // syntax error
}

void h() {
  A a;
  a.f<int>(); // ok
  g(a);
}

Command line: g++ -v -save-temps -c -Wall t.cc

Output:
Reading specs from /usr/lib/gcc-lib/i386-linux/3.2.3/specs
Configured with: ../src/configure -v --enable-languages=c,c++,java,f77,proto,pascal,objc,ada --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.2 --enable-shared --with-system-zlib --enable-nls --without-included-gettext --enable-__cxa_atexit --enable-clocale=gnu --enable-java-gc=boehm --enable-objc-gc i386-linux
Thread model: posix
gcc version 3.2.3 20030210 (Debian prerelease)
 /usr/lib/gcc-lib/i386-linux/3.2.3/cpp0 -lang-c++ -D__GNUG__=3 -D__DEPRECATED -D__EXCEPTIONS -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=3 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -D_GNU_SOURCE -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ t.cc -Wall t.ii
GNU CPP version 3.2.3 20030210 (Debian prerelease) (cpplib) (i386 Linux/ELF)
ignoring nonexistent directory "/usr/i386-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/3.2
 /usr/include/c++/3.2/i386-linux
 /usr/include/c++/3.2/backward
 /usr/local/include
 /usr/lib/gcc-lib/i386-linux/3.2.3/include
 /usr/include
End of search list.
 /usr/lib/gcc-lib/i386-linux/3.2.3/cc1plus -fpreprocessed t.ii -quiet -dumpbase t.cc -Wall -version -o t.s
GNU CPP version 3.2.3 20030210 (Debian prerelease) (cpplib) (i386 Linux/ELF)
GNU C++ version 3.2.3 20030210 (Debian prerelease) (i386-linux)
        compiled by GNU C version 3.2.3 20030210 (Debian prerelease).
t.cc: In function `void g(T)':
t.cc:10: syntax error before `>' token
>How-To-Repeat:
See description.
>Fix:
This an be used as a workaround:

template<typename T, typename V>
struct X {
  static void f(T x) {
    x.f<V>();
  }
};

template<typename T>
void g2(T x) {
  X<T, int>::f(a);
}
>Release-Note:
>Audit-Trail:
>Unformatted:

Re: c++/9887: Syntax error on explicit member function template argument in function template body

[bangerth]

Synopsis: Syntax error on explicit member function template argument in function template body

State-Changed-From-To: open->closed
State-Changed-By: bangerth
State-Changed-When: Mon Mar  3 15:17:04 2003
State-Changed-Why:
    Not a bug. You need to write
        x.template f<int>(); // syntax error
    (note the "template" keyword here).
    
    W.

http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=9887